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MAILX(1)                                  User Commands                                  MAILX(1)



NAME
       mailx - send and receive Internet mail

SYNOPSIS
       mailx [-BDdEFintv~] [-s subject] [-a attachment ] [-c cc-addr] [-b bcc-addr] [-r from-
              addr] [-h hops] [-A account] [-S variable[=value]] to-addr . . .
       mailx [-BDdeEHiInNRv~] [-T name] [-A account] [-S variable[=value]] -f [name]
       mailx [-BDdeEinNRv~] [-A account] [-S variable[=value]] [-u user]

DESCRIPTION
       Mailx is an intelligent mail processing system, which has a command syntax reminiscent  of
       ed(1)  with  lines replaced by messages.  It is based on Berkeley Mail 8.1, is intended to
       provide the functionality of the POSIX mailx command,  and  offers  extensions  for  MIME,
       IMAP,  POP3, SMTP, and S/MIME.  Mailx provides enhanced features for interactive use, such
       as caching and disconnected operation for IMAP, message threading, scoring, and filtering.
       It is also usable as a mail batch language, both for sending and receiving mail.

       The following options are accepted:

       -A name
              Executes  an account command (see below) for name after the startup files have been
              read.

       -a file
              Attach the given file to the message.

       -B     Make standard input and standard output line-buffered.

       -b address
              Send blind carbon copies to list.  List should be a comma-separated list of names.

       -c address
              Send carbon copies to list of users.

       -D     Start in disconnected mode; see  the  description  for  the  disconnected  variable
              option.

       -d     Enables  debugging  messages  and disables the actual delivery of messages.  Unlike
              -v, this option is intended for mailx development only.

       -e     Just check if mail is present in the system mailbox.  If yes, return an exit status
              of zero, else, a non-zero value.

       -E     If an outgoing message does not contain any text in its first or only message part,
              do not send it but discard it silently, effectively setting the skipemptybody vari-
              able  at program startup.  This is useful for sending messages from scripts started
              by cron(8).

       -f [file]
              Read in the contents of the user's mbox (or the  specified  file)  for  processing;
              when  mailx  is  quit,  it writes undeleted messages back to this file.  The string
              file is handled as described for the folder command below.

       -F     Save the message to send in a file named after the local part of the first  recipi-
              ent's address.

       -H     Print header summaries for all messages and exit.

       -h hops
              Invoke  sendmail with the specified hop count.  This option has no effect when SMTP
              is used for sending mail.

       -i     Ignore tty interrupt signals.  This is particularly  useful  when  using  mailx  on
              noisy phone lines.

       -I     Shows  the `Newsgroup:' or `Article-Id:' fields in the header summary.  Only appli-
              cable in combination with -f.

       -n     Inhibits reading /etc/mail.rc upon startup.  This option should  be  activated  for
              mailx  scripts  that  are invoked on more than one machine, because the contents of
              that file may differ between them.

       -N     Inhibits the initial display of message headers when reading mail or editing a mail
              folder.

       -q file
              Start  the  message  with the contents of the specified file.  May be given in send
              mode only.

       -r address
              Sets the From address. Overrides any from  variable  specified  in  environment  or
              startup  files.   Tilde escapes are disabled.  The -r address options are passed to
              the mail transfer agent unless SMTP is used.  This option exists for  compatibility
              only; it is recommended to set the from variable directly instead.

       -R     Opens any folders read-only.

       -s subject
              Specify  subject on command line (only the first argument after the -s flag is used
              as a subject; be careful to quote subjects containing spaces).

       -S variable[=value]
              Sets the internal option variable and, in case of a string option, assigns value to
              it.   Note,  that  when setting from variable, domain name of host is automatically
              added if value does not contain any.  If  you  want  to  enter  from  address  with
              owner's  name,  you  can  use,  for example, following format: -S "from=System User
              <DoNotReply>"

       -T name
              Writes the `Message-Id:' and `Article-Id:' header fields of each  message  read  in
              the  file  name.   Implies  -I.   Compressed files are handled as described for the
              folder command below.

       -t     The message to be sent is expected to contain a message header with  `To:',  `Cc:',
              or  `Bcc:'  fields giving its recipients.  Recipients specified on the command line
              are ignored.

       -u user
              Reads the mailbox of the given user name.

       -v     Verbose mode.  The details of delivery are displayed on the user's terminal.

       -V     Print mailx's version and exit.

       -~     Enable tilde escapes even if not in interactive mode.

   Sending mail
       To send a message to one or more people, mailx can be invoked with arguments which are the
       names  of  people to whom the mail will be sent.  The user is then expected to type in his
       message, followed by an `control-D' at the beginning of a line.  The section below  Reply-
       ing  to  or originating mail, describes some features of mailx available to help when com-
       posing letters.

   Reading mail
       In normal usage mailx is given no arguments and checks the user's mail  out  of  the  post
       office,  then  prints out a one line header of each message found.  The current message is
       initially the first message (numbered 1) and can be printed using the print command  which
       can  be  abbreviated  `p').  The user can move among the messages much as he moves between
       lines in ed(1), with the commands `+' and `-' moving backwards and  forwards,  and  simple
       numbers.

   Disposing of mail
       After examining a message the user can delete `d') the message or reply `r') to it.  Dele-
       tion causes the mailx program to forget about the message.  This is not irreversible;  the
       message can be undeleted `u') by giving its number, or the mailx session can be aborted by
       giving the exit `x') command.  Deleted messages will, however, usually disappear never  to
       be seen again.

   Specifying messages
       Commands  such  as print and delete can be given a list of message numbers as arguments to
       apply to a number of messages at once.  Thus `delete 1 2' deletes messages 1 and 2,  while
       `delete  1-5'  deletes messages 1 through 5.  In sorted or threaded mode (see the sort and
       thread commands), `delete 1-5' deletes the messages that are located between (and  includ-
       ing)  messages  1  through 5 in the sorted/threaded order, as shown in the header summary.
       The following special message names exist:

       :n     All new messages.

       :o     All old messages (any not in state read or new).

       :u     All unread messages.

       :d     All deleted messages (for the undelete command).

       :r     All read messages.

       :f     All `flagged' messages.

       :a     All answered messages (cf. the markanswered variable).

       :t     All messages marked as draft.

       :k     All `killed' messages.

       :j     All messages classified as junk.

       .      The current message.

       ;      The message that was previously the current message.

       ,      The parent message of the current message, that is the message with the  Message-ID
              given  in  the `In-Reply-To:' field or the last entry of the `References:' field of
              the current message.

       -      The next previous undeleted message, or the next previous deleted message  for  the
              undelete  command.   In sorted/threaded mode, the next previous such message in the
              sorted/threaded order.

       +      The next undeleted message, or the next deleted message for the  undelete  command.
              In sorted/threaded mode, the next such message in the sorted/threaded order.

       ^      The first undeleted message, or the first deleted message for the undelete command.
              In sorted/threaded mode, the first such message in the sorted/threaded order.

       $      The last message.  In sorted/threaded mode, the last message in the sorted/threaded
              order.

       &x     In  threaded  mode, selects the message addressed with x, where x is any other mes-
              sage specification, and all messages from the thread that begins at it.  Otherwise,
              it  is identical to x.  If x is omitted, the thread beginning with the current mes-
              sage is selected.

       *      All messages.

       `      All messages that were included in the message list for the previous command.

       /string
              All messages that contain string in the subject field (case ignored).  See also the
              searchheaders  variable.  If string is empty, the string from the previous specifi-
              cation of that type is used again.

       address
              All messages from address.  By default, this is a  case-sensitive  search  for  the
              complete  email address.  If the allnet variable is set, only the local part of the
              addresses is evaluated for the comparison.  Otherwise if the showname  variable  is
              set,  a  case-sensitive search for the complete real name of a sender is performed.
              The IMAP-style (from address) expression can be used instead if  substring  matches
              are desired.

       (criterion)
              All  messages  that satisfy the given IMAP-style SEARCH criterion.  This addressing
              mode is available with all types of  folders;  for  folders  not  located  on  IMAP
              servers,  or  for  servers unable to execute the SEARCH command, mailx will perform
              the search locally.  Strings must  be  enclosed  by  double  quotes  `"'  in  their
              entirety  if they contain white space or parentheses; within the quotes, only back-
              slash `\' is recognized as an escape character.   All  string  searches  are  case-
              insensitive.   When the description indicates that the `envelope' representation of
              an address field is used, this means that the search string is checked against both
              a list constructed as

              ("real name" "source-route" "local-part" "domain-part")

              for  each  address, and the addresses without real names from the respective header
              field.  Criteria can be nested using parentheses.

       (criterion1 criterion2 ... criterionN)
              All messages that satisfy all of the given criteria.

       (or criterion1 criterion2)
              All messages that satisfy either criterion1 or criterion2,  or  both.   To  connect
              more  than  two  criteria  using  `or', (or) specifications have to be nested using
              additional parentheses, as with `(or a (or b c))'; `(or a b c)' means ((a or b) and
              c).   For  a  simple  `or'  operation of independent criteria on the lowest nesting
              level, it is possible to achieve similar effects by using three separate  criteria,
              as with `(a) (b) (c)'.

       (not criterion)
              All messages that do not satisfy criterion.

       (bcc string)
              All  messages  that  contain  string  in  the `envelope' representation of the Bcc:
              field.

       (cc string)
              All messages that contain string in the `envelope' representation of the Cc: field.

       (from string)
              All messages that contain string in the  `envelope'  representation  of  the  From:
              field.

       (subject string)
              All messages that contain string in the Subject: field.

       (to string)
              All messages that contain string in the `envelope' representation of the To: field.

       (header name string)
              All messages that contain string in the specified Name: field.

       (body string)
              All messages that contain string in their body.

       (text string)
              All messages that contain string in their header or body.

       (larger size)
              All messages that are larger than size (in bytes).

       (smaller size)
              All messages that are smaller than size (in bytes).

       (before date)
              All  messages  that  were  received before date; date must be in the form d[d]-mon-
              yyyy, where d[d] is the day of the month as one or two digits, mon is the  name  of
              the  month--one  of  `Jan', `Feb', `Mar', `Apr', `May', `Jun', `Jul', `Aug', `Sep',
              `Oct', `Nov', or `Dec', and yyyy is the year as four digits; e.g. "30-Aug-2004".

       (on date)
              All messages that were received on the specified date.

       (since date)
              All messages that were received since the specified date.

       (sentbefore date)
              All messages that were sent on the specified date.

       (senton date)
              All messages that were sent on the specified date.

       (sentsince date)
              All messages that were sent since the specified date.

       ()     The same criterion as for the previous search.  This specification cannot  be  used
              as part of another criterion.  If the previous command line contained more than one
              independent criterion, the last of those criteria is used.

       A practical method to read a set of messages is to issue a from command  with  the  search
       criteria  first to check for appropriate messages, and to read each single message then by
       typing ``' repeatedly.

   Replying to or originating mail
       The reply command can be used to set up a response to a message, sending it  back  to  the
       person  who  it  was from.  Text the user types in then, up to an end-of-file, defines the
       contents of the message.  While the user is composing a message, mailx treats lines begin-
       ning  with  the character `~' specially.  For instance, typing `~m' (alone on a line) will
       place a copy of the current message into the response right shifting it by a tabstop  (see
       indentprefix  variable,  below).  Other escapes will set up subject fields, add and delete
       recipients to the message, attach files to it and allow the user to escape to an editor to
       revise  the  message  or to a shell to run some commands.  (These options are given in the
       summary below.)

   Ending a mail processing session
       The user can end a mailx session with the quit (`q') command.  Messages  which  have  been
       examined  go  to the user's mbox file unless they have been deleted in which case they are
       discarded.  Unexamined messages go back to the post office.  (See the -f option above).

   Personal and systemwide distribution lists
       It is also possible to create a personal distribution lists so  that,  for  instance,  the
       user  can  send  mail to `cohorts' and have it go to a group of people.  Such lists can be
       defined by placing a line like

               alias cohorts bill ozalp jkf mark kridle@ucbcory

       in the file .mailrc in the user's home directory.  The current list of such aliases can be
       displayed  with the alias command in mailx.  System wide distribution lists can be created
       by editing /etc/aliases, see aliases(5) and sendmail(8); these are  kept  in  a  different
       syntax.   In mail the user sends, personal aliases will be expanded in mail sent to others
       so that they will be able to reply  to  the  recipients.   System  wide  aliases  are  not
       expanded when the mail is sent, but any reply returned to the machine will have the system
       wide alias expanded as all mail goes through sendmail.

   Recipient address specifications
       If the expandaddr option is not set (the default), recipient addresses must  be  names  of
       local mailboxes or Internet mail addresses.

       If  the  expandaddr  option  is set, the following rules apply: When an address is used to
       name a recipient (in any of To, Cc, or Bcc), names of local  mail  folders  and  pipes  to
       external  commands  can  also be specified; the message text is then written to them.  The
       rules are: Any name which starts with a `|' character specifies a pipe, the command string
       following  the  `|'  is  executed and the message is sent to its standard input; any other
       name which contains a `@' character is treated as a mail address;  any  other  name  which
       starts  with  a `+' character specifies a folder name; any other name which contains a `/'
       character but no `!'  or `%' character before also specifies a folder name;  what  remains
       is  treated as a mail address.  Compressed folders are handled as described for the folder
       command below.

   Network mail (Internet / ARPA, UUCP, Berknet)
       See mailaddr(7) for a description of network addresses.  Mailx has  a  number  of  options
       which  can  be set in the .mailrc file to alter its behavior; thus `set askcc' enables the
       askcc feature.  (These options are summarized below).

   MIME types
       For any outgoing attachment, mailx tries to determine the content type.  It does  this  by
       reading MIME type files whose lines have the following syntax:

               type/subtype      extension [extension . . .]

       where  type/subtype are strings describing the file contents, and extension is the part of
       a filename starting after the last dot.  Any line not immediately beginning with an  ASCII
       alphabetical character is ignored by mailx.  If there is a match with the extension of the
       file to attach, the given type/subtype pair is used.  Otherwise, or if the filename has no
       extension,  the  content  types text/plain or application/octet-stream are used, the first
       for text or international text files, the second for any  file  that  contains  formatting
       characters other than newlines and horizontal tabulators.

   Character sets
       Mailx  normally  detects  the character set of the terminal using the LC_CTYPE locale set-
       ting.  If the locale cannot be used appropriately, the ttycharset variable should  be  set
       to  provide an explicit value.  When reading messages, their text is converted to the ter-
       minal character set if possible.  Unprintable characters and illegal  byte  sequences  are
       detected and replaced by Unicode substitute characters or question marks unless the print-
       all-chars is set at initialization time.

       The character set for outgoing messages is not necessarily the same as the one used on the
       terminal.   If an outgoing text message contains characters not representable in US-ASCII,
       the character set being used must be declared within its header.  Permissible  values  can
       be  declared using the sendcharsets variable, separated by commas; mailx tries each of the
       values in order and uses the first appropriate one.  If the  message  contains  characters
       that  cannot  be  represented  in any of the given character sets, the message will not be
       sent, and its text will be saved to the `dead.letter' file.   Messages  that  contain  NUL
       bytes are not converted.

       Outgoing  attachments  are converted if they are plain text.  If the sendcharsets variable
       contains more than one character set name, the ~@ tilde escape will ask for the  character
       sets for individual attachments if it is invoked without arguments.

       Best  results  are usually achieved when mailx is run in a UTF-8 locale on a UTF-8 capable
       terminal.  In this setup, characters from various countries can be displayed, while it  is
       still possible to use more simple character sets for sending to retain maximum compatibil-
       ity with older mail clients.

   Commands
       Each command is typed on a line by itself, and may take arguments  following  the  command
       word.  The command need not be typed in its entirety - the first command which matches the
       typed prefix is used.  For commands which take message lists as arguments, if  no  message
       list is given, then the next message forward which satisfies the command's requirements is
       used.  If there are no messages forward of the current message, the search proceeds  back-
       wards,  and  if  there  are no good messages at all, mailx types `applicable messages' and
       aborts the command.  If the command begins with a # sign, the line is ignored.

       The arguments to commands can be quoted, using the following methods:

       o      An argument can be enclosed between paired double-quotes ""  or  single-quotes  '';
              any  white  space,  shell word expansion, or backslash characters within the quotes
              are treated literally as part of the argument.  A double-quote will be treated lit-
              erally  within  single-quotes and vice versa. These special properties of the quote
              marks occur only when they are paired at the beginning and end of the argument.

       o      A backslash outside of the enclosing quotes is discarded and the following  charac-
              ter is treated literally as part of the argument.

       o      An  unquoted  backslash at the end of a command line is discarded and the next line
              continues the command.

       Filenames, where expected, are subjected to the following transformations, in sequence:

       o      If the filename begins with an unquoted plus  sign,  and  the  folder  variable  is
              defined,  the  plus  sign will be replaced by the value of the folder variable fol-
              lowed by a slash. If the folder variable is unset or is set to null,  the  filename
              will be unchanged.

       o      Shell  word expansions are applied to the filename.  If more than a single pathname
              results from this expansion and  the  command  is  expecting  one  file,  an  error
              results.

       The following commands are provided:

       -      Print  out  the preceding message.  If given a numeric argument n, goes to the n'th
              previous message and prints it.

       ?      Prints a brief summary of commands.

       !      Executes the shell (see sh(1) and csh(1)) command which follows.

       |      A synonym for the pipe command.

       account
              (ac) Creates, selects or lists an email account.  An account is formed by  a  group
              of commands, primarily of those to set variables.  With two arguments, of which the
              second is a `{', the first argument gives an account name, and the following  lines
              create  a  group  of commands for that account until a line containing a single `}'
              appears.  With one argument, the previously  created  group  of  commands  for  the
              account  name  is executed, and a folder command is executed for the system mailbox
              or inbox of that account.  Without arguments, the list of accounts and  their  con-
              tents are printed.  As an example,

                  account myisp {
                      set folder=imaps://mylogin AT imap.example
                      set record=+Sent
                      set from="myname AT myisp.example (My Name)"
                      set smtp=smtp.myisp.example
                  }

              creates an account named `myisp' which can later be selected by specifying `account
              myisp'.

       alias  (a) With no arguments, prints out all currently-defined aliases.   With  one  argu-
              ment,  prints  out that alias.  With more than one argument, creates a new alias or
              changes an old one.

       alternates
              (alt) The alternates command  is  useful  if  the  user  has  accounts  on  several
              machines.   It  can be used to inform mailx that the listed addresses all belong to
              the invoking user.  When he replies to messages, mailx will not send a copy of  the
              message  to  any of the addresses listed on the alternates list.  If the alternates
              command is given with no argument, the current set of alternate names is displayed.

       answered
              (ans) Takes a message list and marks each message as a having been answered.   This
              mark  has  no  technical  meaning in the mail system; it just causes messages to be
              marked in the header summary, and makes them specially addressable.

       cache  Only applicable to cached IMAP mailboxes; takes a message list and reads the speci-
              fied messages into the IMAP cache.

       call   Calls a macro (see the define command).

       cd     Same as chdir.

       certsave
              Only  applicable  to  S/MIME signed messages.  Takes a message list and a file name
              and saves the certificates contained within the message  signatures  to  the  named
              file  in both human-readable and PEM format.  The certificates can later be used to
              send encrypted messages to the messages' originators by setting the  smime-encrypt-
              user@host variable.

       chdir  (ch)  Changes  the  user's  working  directory  to that specified, if given.  If no
              directory is given, then changes to the user's login directory.

       classify
              (cl) Takes a list of messages and examines their contents  for  characteristics  of
              junk mail using Bayesian filtering.  Messages considered to be junk are then marked
              as such.  The junk mail database is not changed.

       collapse
              (coll) Only applicable to threaded mode.   Takes  a  message  list  and  makes  all
              replies  to  these messages invisible in header summaries, unless they are in state
              `new'.

       connect
              (conn) If operating in disconnected mode on an IMAP mailbox, switch to online  mode
              and  connect  to  the  mail  server  while  retaining  the mailbox status.  See the
              description of the disconnected variable for more information.

       copy   (c) The copy command does the same thing that save does, except that  it  does  not
              mark the messages it is used on for deletion when the user quits.  Compressed files
              and IMAP mailboxes are handled as described for the folder command.

       Copy   (C) Similar to copy, but saves the messages in a file named after the local part of
              the sender address of the first message.

       decrypt
              (dec)  For unencrypted messages, this command is identical to copy.  Encrypted mes-
              sages are first decrypted, if possible, and then copied.

       Decrypt
              (Dec) Similar to decrypt, but saves the messages in a file named  after  the  local
              part of the sender address of the first message.

       define (def) Defines a macro.  A macro definition is a sequence of commands in the follow-
              ing form:

                  define name {
                      command1
                      command2
                      ...
                      commandN
                  }

              Once defined, a macro can be explicitly invoked using the call command, or  can  be
              implicitly invoked by setting the folder-hook or folder-hook-fullname variables.

       defines
              Prints the currently defined macros including their contents.

       delete (d)  Takes  a  list of messages as argument and marks them all as deleted.  Deleted
              messages will not be saved in mbox, nor will they be available for most other  com-
              mands.

       discard
              Same as ignore.

       disconnect
              (disco) If operating in online mode on an IMAP mailbox, switch to disconnected mode
              while retaining the mailbox status.  See the description of the disconnected  vari-
              able for more information.  A list of messages may optionally be given as argument;
              the respective messages are then read into  the  cache  before  the  connection  is
              closed.  Thus `disco *' makes the entire current mailbox available for disconnected
              use.

       dp or dt
              Deletes the current message and prints the next message.  If there is no next  mes-
              sage, mailx says `at EOF'.

       draft  Takes a message list and marks each message as a draft.  This mark has no technical
              meaning in the mail system; it just causes messages to be marked in the header sum-
              mary, and makes them specially addressable.

       echo   Echoes its arguments, resolving special names as documented for the folder command.
              The escape sequences `\a', `\b', `\c', `\f', `\n',  `\r',  `\t',  `\v',  `\\',  and
              `\0num' are interpreted as with the echo(1) command.

       edit   (e) Takes a list of messages and points the text editor at each one in turn.  Modi-
              fied contents are discarded unless the writebackedited variable is set.

       else   Marks the end of the then-part of an if statement and the beginning of the part  to
              take effect if the condition of the if statement is false.

       endif  Marks the end of an if statement.

       exit   (ex  or  x)  Effects  an immediate return to the Shell without modifying the user's
              system mailbox, his mbox file, or his edit file in -f.

       file   (fi) The same as folder.

       flag   (fl) Takes a message list and marks the messages as  `flagged'  for  urgent/special
              attention.   This  mark has no technical meaning in the mail system; it just causes
              messages to be highlighted in the header summary, and makes them specially address-
              able.

       folders
              With  no arguments, list the names of the folders in the folder directory.  With an
              existing folder as an argument, lists then names of folders below the named folder;
              e.g.  the  command  `folders  @' lists the folders on the base level of the current
              IMAP server.  See also the imap-list-depth variable.

       folder (fold) The folder command switches to a new mail file or  folder.   With  no  argu-
              ments,  it  tells  the  user which file he is currently reading.  If an argument is
              given, it will write out changes (such as deletions) the user has made in the  cur-
              rent  file  and  read in the new file.  Some special conventions are recognized for
              the name.  # means the previous file, % means the invoking user's  system  mailbox,
              %user means user's system mailbox, & means the invoking user's mbox file, and +file
              means a file in the folder directory.  %:filespec expands  to  the  same  value  as
              filespec,  but  the  file is handled as a system mailbox e. g. by the mbox and save
              commands.  If the name matches one of the strings defined with  the  shortcut  com-
              mand,  it  is replaced by its long form and expanded.  If the name ends with .gz or
              .bz2, it is treated as compressed with gzip(1) or  bzip2(1),  respectively.   Like-
              wise, if name does not exist, but either name.gz or name.bz2 exists, the compressed
              file is used.  If name refers to a directory with the subdirectories `tmp',  `new',
              and `cur', it is treated as a folder in maildir format.  A name of the form

                     protocol://[user@]host[:port][/file]

              is  taken  as  an Internet mailbox specification.  The supported protocols are cur-
              rently imap (IMAP v4r1), imaps (IMAP with SSL/TLS  encryption),  pop3  (POP3),  and
              pop3s (POP3 with SSL/TLS encryption).  If user contains special characters, in par-
              ticular `/' or `%', they must be escaped in URL notation, as `%2F' or  `%25'.   The
              optional  file  part applies to IMAP only; if it is omitted, the default `INBOX' is
              used.  If mailx is connected to an IMAP server, a name of the form @mailbox  refers
              to the mailbox on that server.  If the `folder' variable refers to an IMAP account,
              the special name `%' selects the `INBOX' on that account.

       Followup
              (F) Similar to Respond, but saves the message in a file named after the local  part
              of the first recipient's address.

       followup
              (fo) Similar to respond, but saves the message in a file named after the local part
              of the first recipient's address.

       followupall
              Similar to followup, but responds to all recipients regardless  of  the  flipr  and
              Replyall variables.

       followupsender
              Similar  to  Followup,  but responds to the sender only regardless of the flipr and
              Replyall variables.

       forward
              (fwd) Takes a message and the address of a recipient and forwards  the  message  to
              him.   The  text of the original message is included in the new one, with the value
              of the fwdheading variable printed before.  The fwdignore  and  fwdretain  commands
              specify  which  header fields are included in the new message.  Only the first part
              of a multipart message is included unless the forward-as-attachment option is set.

       Forward
              (Fwd) Similar to forward, but saves the message in a file  named  after  the  local
              part of the recipient's address.

       from   (f)  Takes  a  list of messages and prints their message headers, piped through the
              pager if the output does not fit on the screen.

       fwdignore
              Specifies which header fields are to be ignored with  the  forward  command.   This
              command has no effect when the forward-as-attachment option is set.

       fwdretain
              Specifies  which  header  fields  are  to  be  retained  with  the forward command.
              fwdretain overrides fwdignore.  This command has no  effect  when  the  forward-as-
              attachment option is set.

       good   (go)  Takes  a list of messages and marks all of them as not being junk mail.  Data
              from these messages is then inserted into the junk mail database for future classi-
              fication.

       headers
              (h)  Lists  the  current  range of headers, which is an 18-message group.  If a `+'
              argument is given, then the next 18-message group is printed, and if a `-' argument
              is given, the previous 18-message group is printed.

       help   A synonym for ?.

       hold   (ho, also preserve) Takes a message list and marks each message therein to be saved
              in the user's system mailbox instead of in mbox.  Does not override the delete com-
              mand.   mailx  deviates from the POSIX standard with this command, as a `next' com-
              mand issued after `hold' will display the following message, not the current one.

       if     Commands in mailx's startup  files  can  be  executed  conditionally  depending  on
              whether the user is sending or receiving mail with the if command.  For example:

                      if receive
                              commands . . .
                      endif

              An else form is also available:

                      if receive
                              commands . . .
                      else
                              commands . . .
                      endif

              Note  that the only allowed conditions are receive, send, and term (execute command
              if standard input is a tty).

       ignore Add the list of header fields named to the ignored  list.   Header  fields  in  the
              ignore  list  are not printed on the terminal when a message is printed.  This com-
              mand is very handy for suppression of certain machine-generated header fields.  The
              Type  and  Print commands can be used to print a message in its entirety, including
              ignored fields.  If ignore is executed with no arguments, it lists the current  set
              of ignored fields.

       imap   Sends  command  strings directly to the current IMAP server.  Mailx operates always
              in IMAP selected state on the current mailbox; commands that change this will  pro-
              duce undesirable results and should be avoided.  Useful IMAP commands are:

              create Takes the name of an IMAP mailbox as an argument and creates it.

              getquotaroot
                     Takes  the name of an IMAP mailbox as an argument and prints the quotas that
                     apply to the mailbox.  Not all IMAP servers support this command.

              namespace
                     Takes no arguments and prints the  Personal  Namespaces,  the  Other  User's
                     Namespaces,  and  the  Shared Namespaces.  Each namespace type is printed in
                     parentheses; if there are multiple namespaces of the same type, inner paren-
                     theses  separate them.  For each namespace, a namespace prefix and a hierar-
                     chy separator is listed.  Not all IMAP servers support this command.

       inc    Same as newmail.

       junk   (j) Takes a list of messages and marks all of them as junk mail.  Data  from  these
              messages is then inserted into the junk mail database for future classification.

       kill   (k)  Takes a list of messages and `kills' them.  Killed messages are not printed in
              header summaries, and are ignored by the next command.  The kill command also  sets
              the  score  of the messages to negative infinity, so that subsequent score commands
              will not unkill them again.  Killing is only effective for the current session on a
              folder; when it is quit, all messages are automatically unkilled.

       list   Prints the names of all available commands.

       Mail   (M)  Similar to mail, but saves the message in a file named after the local part of
              the first recipient's address.

       mail   (m) Takes as argument login names and distribution group names and  sends  mail  to
              those people.

       mbox   Indicate  that a list of messages be sent to mbox in the user's home directory when
              mailx is quit.  This is the default action for messages if unless the  hold  option
              is set.  mailx deviates from the POSIX standard with this command, as a `next' com-
              mand issued after `mbox' will display the following message, not the current one.

       move   (mv) Acts like copy, but marks the messages for deletion if they  were  transferred
              successfully.

       Move   (Mv)  Similar  to move, but moves the messages to a file named after the local part
              of the sender address of the first message.

       newmail
              Checks for new mail in the current folder without committing  any  changes  before.
              If  new  mail is present, a message is printed.  If the header variable is set, the
              headers of each new message are also printed.

       next   (n) like + or CR) Goes to the next message in sequence and types it.  With an argu-
              ment list, types the next matching message.

       New    Same as unread.

       new    Same as unread.

       online Same as connect.

       noop   If the current folder is located on an IMAP or POP3 server, a NOOP command is sent.
              Otherwise, no operation is performed.

       Pipe   (Pi) Like pipe but also pipes ignored header fields and all parts  of  MIME  multi-
              part/alternative messages.

       pipe   (pi)  Takes  a  message list and a shell command and pipes the messages through the
              command.  Without an argument, the current message is  piped  through  the  command
              given by the cmd variable.  If the  page variable is set, every message is followed
              by a formfeed character.

       preserve
              (pre) A synonym for hold.

       Print  (P) Like print but also prints out ignored header fields and all parts of MIME mul-
              tipart/alternative messages.  See also print, ignore, and retain.

       print  (p) Takes a message list and types out each message on the user's terminal.  If the
              message is a MIME multipart message, all parts with a content  type  of  `text'  or
              `message'  are  shown, the other are hidden except for their headers.  Messages are
              decrypted and converted to the terminal character set if necessary.

       probability
              (prob) For each word given as argument, the contents  of  its  junk  mail  database
              entry are printed.

       quit   (q)  Terminates  the  session, saving all undeleted, unsaved messages in the user's
              mbox file in his login directory, preserving all messages marked with hold or  pre-
              serve  or  never  referenced in his system mailbox, and removing all other messages
              from his system mailbox.  If new mail has arrived during the session,  the  message
              `You  have  new  mail' is given.  If given while editing a mailbox file with the -f
              flag, then the edit file is rewritten.  A return to the Shell is  effected,  unless
              the  rewrite  of  edit  file fails, in which case the user can escape with the exit
              command.

       redirect
              (red) Same as resend.

       Redirect
              (Red) Same as Resend.

       remove (rem) Removes the named folders.  The user is asked for confirmation in interactive
              mode.

       rename (ren)  Takes  the  name  of  an existing folder and the name for the new folder and
              renames the first to the second one.  Both folders must be of  the  same  type  and
              must be located on the current server for IMAP.

       Reply  (R)  Reply  to originator.  Does not reply to other recipients of the original mes-
              sage.

       reply  (r) Takes a message list and sends mail to the sender and  all  recipients  of  the
              specified message.  The default message must not be deleted.

       replyall
              Similar  to  reply,  but  responds  to  all  recipients regardless of the flipr and
              Replyall variables.

       replysender
              Similar to Reply, but responds to the sender  only  regardless  of  the  flipr  and
              Replyall variables.

       Resend Like  resend,  but  does  not  add any header lines.  This is not a way to hide the
              sender's identity, but useful for sending a message again to the same recipients.

       resend Takes a list of messages and a user name and sends each message to the named  user.
              `Resent-From:'  and related header fields are prepended to the new copy of the mes-
              sage.

       Respond
              Same as Reply.

       respond
              Same as reply.

       respondall
              Same as replyall.

       respondsender
              Same as replysender.

       retain Add the list of header fields named to the retained list.  Only the  header  fields
              in  the retain list are shown on the terminal when a message is printed.  All other
              header fields are suppressed.  The Type and Print commands can be used to  print  a
              message  in  its  entirety.   If retain is executed with no arguments, it lists the
              current set of retained fields.

       Save   (S) Similar to save, but saves the messages in a file named after the local part of
              the sender of the first message instead of taking a filename argument.

       save   (s) Takes a message list and a filename and appends each message in turn to the end
              of the file.  If no filename is given, the mbox file  is  used.   The  filename  in
              quotes, followed by the line count and character count is echoed on the user's ter-
              minal.  If editing a system mailbox, the messages are marked  for  deletion.   Com-
              pressed  files  and IMAP mailboxes are handled as described for the -f command line
              option above.

       savediscard
              Same as saveignore.

       saveignore
              Saveignore is to save what ignore is to print and type.  Header fields thus  marked
              are  filtered  out  when  saving  a message by save or when automatically saving to
              mbox.  This command should only be applied to header fields  that  do  not  contain
              information  needed  to  decode  the message, as MIME content fields do.  If saving
              messages on an IMAP account, ignoring fields makes it impossible to copy  the  data
              directly on the server, thus operation usually becomes much slower.

       saveretain
              Saveretain  is to save what retain is to print and type.  Header fields thus marked
              are the only ones saved with a message when saving by save  or  when  automatically
              saving  to  mbox.   Saveretain  overrides  saveignore.   The use of this command is
              strongly discouraged since it may strip header fields that are needed to decode the
              message correctly.

       score  (sc)  Takes  a  message list and a floating point number and adds the number to the
              score of each given message.  All messages start  at  score  0  when  a  folder  is
              opened.   When  the  score  of  a message becomes negative, it is `killed' with the
              effects described for the kill command; otherwise if it  was  negative  before  and
              becomes  positive,  it  is  `unkilled'.   Scores only refer to the currently opened
              instance of a folder.

       set    (se) With no arguments, prints all variable values, piped through the pager if  the
              output  does  not fit on the screen.  Otherwise, sets option.  Arguments are of the
              form option=value (no space before or after =) or option.  Quotation marks  may  be
              placed  around  any  part of the assignment statement to quote blanks or tabs, i.e.
              `set indentprefix="->"'.  If an argument begins with no, as in  `set  nosave',  the
              effect  is  the  same  as invoking the unset command with the remaining part of the
              variable (`unset save').

       seen   Takes a message list and marks all messages as having been read.

       shell  (sh) Invokes an interactive version of the shell.

       shortcut
              Defines a shortcut name and its string for expansion, as described for  the  folder
              command.  With no arguments, a list of defined shortcuts is printed.

       show   (Sh)  Like print, but performs neither MIME decoding nor decryption so that the raw
              message text is shown.

       size   Takes a message list and prints out the size in characters of each message.

       sort   Create a sorted representation of the current folder, and change the  next  command
              and  the  addressing  modes  such  that they refer to messages in the sorted order.
              Message numbers are the same as in regular mode.  If the header variable is set,  a
              header summary in the new order is also printed.  Possible sorting criteria are:

              date   Sort  the  messages  by  their  `Date:' field, that is by the time they were
                     sent.

              from   Sort messages by the value of their `From:' field, that is by the address of
                     the  sender.   If  the  showname variable is set, the sender's real name (if
                     any) is used.

              size   Sort the messages by their size.

              score  Sort the messages by their score.

              status Sort the messages by their message status (new, read, old, etc.).

              subject
                     Sort the messages by their subject.

              thread Create a threaded order, as with the thread command.

              to     Sort messages by the value of their `To:' field, that is by the  address  of
                     the  recipient.   If the showname variable is set, the recipient's real name
                     (if any) is used.

              If no argument is given, the current sorting criterion is printed.

       source The source command reads commands from a file.

       thread (th) Create a threaded representation of the current folder, i.e.  indent  messages
              that  are replies to other messages in the header display, and change the next com-
              mand and the addressing modes such that they refer  to  messages  in  the  threaded
              order.  Message numbers are the same as in unthreaded mode.  If the header variable
              is set, a header summary in threaded order is also printed.

       top    Takes a message list and prints the top few lines of each.   The  number  of  lines
              printed is controlled by the variable toplines and defaults to five.

       touch  Takes  a  message  list  and marks the messages for saving in the mbox file.  mailx
              deviates from the POSIX standard with this command,  as  a  `next'  command  issued
              after `mbox' will display the following message, not the current one.

       Type   (T) Identical to the Print command.

       type   (t) A synonym for print.

       unalias
              Takes  a list of names defined by alias commands and discards the remembered groups
              of users.  The group names no longer have any significance.

       unanswered
              Takes a message list and marks each message as not having been answered.

       uncollapse
              (unc) Only applicable to threaded mode.  Takes a message list and makes the message
              and  all  replies  to it visible in header summaries again.  When a message becomes
              the current message, it is automatically made visible.  Also when  a  message  with
              collapsed replies is printed, all of these are automatically uncollapsed.

       undef  Undefines each of the named macros.  It is not an error to use a name that does not
              belong to one of the currently defined macros.

       undelete
              (u) Takes a message list and marks each message as not being deleted.

       undraft
              Takes a message list and marks each message as a draft.

       unflag Takes a message list and marks each message as not being `flagged'.

       unfwdignore
              Removes the header field names from the list of ignored fields for the forward com-
              mand.

       unfwdretain
              Removes  the  header  field  names from the list of retained fields for the forward
              command.

       ungood Takes a message list and undoes the effect of a good command  that  was  previously
              applied on exactly these messages.

       unignore
              Removes the header field names from the list of ignored fields.

       unjunk Takes  a  message  list and undoes the effect of a junk command that was previously
              applied on exactly these messages.

       unkill Takes a message list and `unkills' each message.  Also sets the score of  the  mes-
              sages to 0.

       Unread Same as unread.

       unread (U) Takes a message list and marks each message as not having been read.

       unretain
              Removes the header field names from the list of retained fields.

       unsaveignore
              Removes the header field names from the list of ignored fields for saving.

       unsaveretain
              Removes the header field names from the list of retained fields for saving.

       unset  Takes  a  list of option names and discards their remembered values; the inverse of
              set.

       unshortcut
              Deletes the shortcut names given as arguments.

       unsort Disable sorted or threaded mode (see the sort and thread commands), return to  nor-
              mal message order and, if the header variable is set, print a header summary.

       unthread
              (unth) Same as unsort.

       verify (verif)  Takes  a  message  list and verifies each message.  If a message is not an
              S/MIME signed message, verification will fail for  it.   The  verification  process
              checks if the message was signed using a valid certificate, if the message sender's
              email address matches one of those contained within the  certificate,  and  if  the
              message content has been altered.

       visual (v)  Takes a message list and invokes the display editor on each message.  Modified
              contents are discarded unless the writebackedited variable is set.

       write  (w) For conventional messages, the body without all headers is written.  The output
              is  decrypted and converted to its native format, if necessary.  If the output file
              exists, the text is appended.--If a message is in MIME multipart format, its  first
              part is written to the specified file as for conventional messages, and the user is
              asked for a filename to save each other part; if the contents of the first part are
              not  to  be  saved,  `write  /dev/null' can be used.  For the second and subsequent
              parts, if the filename given starts with a `|' character, the part is piped through
              the  remainder  of the filename interpreted as a shell command.  In non-interactive
              mode, only the parts of the multipart message that have a  filename  given  in  the
              part  header  are  written, the other are discarded.  The original message is never
              marked for deletion in the originating mail folder.  For attachments, the  contents
              of the destination file are overwritten if the file previously existed.  No special
              handling of compressed files is performed.

       xit    (x) A synonym for exit.

       z      Mailx presents message headers in windowfuls as described under  the  headers  com-
              mand.   The  z  command  scrolls to the next window of messages.  If an argument is
              given, it specifies the window to use.  A number prefixed by `+' or  `-'  indicates
              that  the window is calculated in relation to the current position.  A number with-
              out a prefix specifies an absolute window number, and a `$' lets  mailx  scroll  to
              the last window of messages.

       Z      Similar to z, but scrolls to the next or previous window that contains at least one
              new or `flagged' message.

   Tilde escapes
       Here is a summary of the tilde escapes, which are used when composing messages to  perform
       special functions.  Tilde escapes are only recognized at the beginning of lines.  The name
       `tilde escape' is somewhat of a misnomer since the actual escape character can be  set  by
       the option escape.

       ~!command
              Execute the indicated shell command, then return to the message.

       ~.     Same effect as typing the end-of-file character.

       ~<filename
              Identical to ~r.

       ~<!command
              Command is executed using the shell.  Its standard output is inserted into the mes-
              sage.

       ~@ [filename . . . ]
              With no arguments, edit the attachment list.  First, the user can edit all existing
              attachment  data.   If  an attachment's file name is left empty, that attachment is
              deleted from the list.  When the end of the attachment list is reached, mailx  will
              ask  for further attachments, until an empty file name is given.  If filename argu-
              ments are specified, all of them are appended to the end of  the  attachment  list.
              Filenames which contain white space can only be specified with the first method (no
              filename arguments).

       ~A     Inserts the string contained in the Sign variable (same as `~i Sign').  The  escape
              sequences `\t' (tabulator) and `\n' (newline) are understood.

       ~a     Inserts  the string contained in the sign variable (same as `~i sign').  The escape
              sequences `\t' (tabulator) and `\n' (newline) are understood.

       ~bname . . .
              Add the given names to the list of carbon copy recipients but do not make the names
              visible in the Cc: line (`blind' carbon copy).

       ~cname . . .
              Add the given names to the list of carbon copy recipients.

       ~d     Read the file `dead.letter' from the user's home directory into the message.

       ~e     Invoke  the text editor on the message collected so far.  After the editing session
              is finished, the user may continue appending text to the message.

       ~fmessages
              Read the named messages into the message being sent.  If no messages are specified,
              read  in  the  current  message.   Message  headers currently being ignored (by the
              ignore or retain command) are not included.  For MIME multipart messages, only  the
              first printable part is included.

       ~Fmessages
              Identical to ~f, except all message headers and all MIME parts are included.

       ~h     Edit  the message header fields `To:', `Cc:', `Bcc:', and `Subject:' by typing each
              one in turn and allowing the user to append text to the end or modify the field  by
              using the current terminal erase and kill characters.

       ~H     Edit the message header fields `From:', `Reply-To:', `Sender:', and `Organization:'
              in the same manner as described for ~h.  The default values for these fields origi-
              nate from the from, replyto, and ORGANIZATION variables.  If this tilde command has
              been used, changing the variables has no effect on the current message anymore.

       ~ivariable
              Insert the value of the specified variable into the message adding a newline  char-
              acter  at  the  end.   If the variable is unset or empty, the message remains unal-
              tered.  The escape sequences `\t' (tabulator) and `\n' (newline) are understood.

       ~mmessages
              Read the named messages into the message being sent, indented by a tab  or  by  the
              value  of  indentprefix.   If  no messages are specified, read the current message.
              Message headers currently being ignored (by the ignore or retain command)  are  not
              included.  For MIME multipart messages, only the first printable part is included.

       ~Mmessages
              Identical to ~m, except all message headers and all MIME parts are included.

       ~p     Print  out  the message collected so far, prefaced by the message header fields and
              followed by the attachment list, if any.  If the message text is  longer  than  the
              screen size, it is piped through the pager.

       ~q     Abort  the  message  being sent, copying the message to `dead.letter' in the user's
              home directory if save is set.

       ~rfilename
              Read the named file into the message.

       ~sstring
              Cause the named string to become the current subject field.

       ~tname . . .
              Add the given names to the direct recipient list.

       ~v     Invoke an alternate editor (defined by the VISUAL option) on the message  collected
              so  far.   Usually, the alternate editor will be a screen editor.  After the editor
              is quit, the user may resume appending text to the end of the message.

       ~wfilename
              Write the message onto the named file.  If the file exists, the message is appended
              to it.

       ~x     Same as ~q, except that the message is not saved to the `dead.letter' file.

       ~|command
              Pipe  the  message through the command as a filter.  If the command gives no output
              or terminates abnormally, retain the original text of  the  message.   The  command
              fmt(1) is often used as command to rejustify the message.

       ~:mailx-command
              Execute the given mailx command.  Not all commands, however, are allowed.

       ~_mailx-command
              Identical to ~:.

       ~~string
              Insert  the  string  of  text in the message prefaced by a single ~.  If the escape
              character has been changed, that character must be doubled in order to send  it  at
              the beginning of a line.

   Variable options
       Options are controlled via set and unset commands, see their entries for a syntax descrip-
       tion.  An option is also set if it is passed to mailx as part of the environment (this  is
       not  restricted  to  specific  variables  as  in  the POSIX standard).  A value given in a
       startup file overrides a value imported from the environment, but it is  not  possible  to
       unset  an  environment variable in a startup file.  Options may be either binary, in which
       case it is only significant to see whether they are set or not; or string, in  which  case
       the actual value is of interest.

   Binary options
       The binary options include the following:

       allnet Causes only the local part to be evaluated when comparing addresses.

       append Causes  messages  saved  in  mbox  to be appended to the end rather than prepended.
              This should always be set.

       ask or asksub
              Causes mailx to prompt for the subject of each message sent.  If the user  responds
              with simply a newline, no subject field will be sent.

       askatend
              Causes  the prompts for `Cc:' and `Bcc:' lists to appear after the message has been
              edited.

       askattach
              If set, mailx asks for files to attach at the end of each message.  Responding with
              a newline indicates not to include an attachment.

       askcc  Causes the user to be prompted for additional carbon copy recipients (at the end of
              each message if askatend or bsdcompat is set).  Responding with a newline indicates
              the user's satisfaction with the current list.

       askbcc Causes  the user to be prompted for additional blind carbon copy recipients (at the
              end of each message if askatend or bsdcompat is set).  Responding  with  a  newline
              indicates the user's satisfaction with the current list.

       asksign
              Causes  the  user  to be prompted if the message is to be signed at the end of each
              message.  The smime-sign variable is ignored when this variable is set.

       autocollapse
              Causes threads to be collapsed automatically when threaded mode is entered (see the
              collapse command).

       autoinc
              Same as newmail.

       autoprint
              Causes  the  delete command to behave like dp - thus, after deleting a message, the
              next one will be typed automatically.

       autothread
              Causes threaded mode (see the thread command) to be entered  automatically  when  a
              folder is opened.

       bang   Enables  the substitution of `!'  by the contents of the last command line in shell
              escapes.

       bsdannounce
              Causes automatic display of a header summary after executing a folder command.

       bsdcompat
              Sets some cosmetical features to traditional BSD style; has the same affect as set-
              ting  `askatend'  and  all  other  variables prefixed with `bsd', setting prompt to
              `& ', and changing the default pager to more.

       bsdflags
              Changes the letters printed in the first column of a header summary to  traditional
              BSD style.

       bsdheadline
              Changes the display of columns in a header summary to traditional BSD style.

       bsdmsgs
              Changes some informational messages to traditional BSD style.

       bsdorder
              Causes  the `Subject:' field to appear immediately after the `To:' field in message
              headers and with the ~h tilde command.

       bsdset Changes the output format of the set command to traditional BSD style.

       chained-junk-tokens
              Normally, the Bayesian junk mail filter bases its classifications  on  single  word
              tokens extracted from messages.  If this option is set, adjacent words are combined
              to pairs, which are then used as additional  tokens.   This  usually  improves  the
              accuracy of the filter, but also increases the junk mail database five- to tenfold.

       datefield
              The  date  in  a header summary is normally the date of the mailbox `From ' line of
              the message.  If this variable is set, the date as  given  in  the  `Date:'  header
              field is used, converted to local time.

       debug  Prints  debugging  messages  and  disables the actual delivery of messages.  Unlike
              verbose, this option is intended for mailx development only.

       disconnected
              When an IMAP mailbox is selected and this variable is set,  no  connection  to  the
              server  is  initiated.   Instead,  data is obtained from the local cache (see imap-
              cache).  Mailboxes that are not present in the cache and messages that have not yet
              entirely been fetched from the server are not available; to fetch all messages in a
              mailbox at once, the command `copy * /dev/null' can be used while still  in  online
              mode.   Changes that are made to IMAP mailboxes in disconnected mode are queued and
              committed later when a connection to that server is opened in  online  mode.   This
              procedure  is  not  completely reliable since it cannot be guaranteed that the IMAP
              unique identifiers (UIDs) on the server still match the ones in the cache  at  that
              time.  Data is saved to `dead.letter' when this problem occurs.

       disconnected-user@host
              The  specified account is handled as described for the disconnected variable above,
              but other accounts are not affected.

       dot    The binary option dot causes mailx to interpret a period alone on  a  line  as  the
              terminator of a message the user is sending.

       editheaders
              When  a  message  is  edited  while  being  composed, its header is included in the
              editable text.  `To:', `Cc:', `Bcc:', `Subject:', `From:', `Reply-To:',  `Sender:',
              and  'Organization:'  fields  are  accepted  within  the  header,  other fields are
              ignored.

       emptybox
              If set, an empty mailbox file is not removed.  This may improve the  interoperabil-
              ity with other mail user agents when using a common folder directory.

       emptystart
              If the mailbox is empty, mailx normally prints `No mail for user' and exits immedi-
              ately.  If this option is set, mailx starts even with an empty mailbox.

       expandaddr
              Causes mailx to expand message recipient addresses, as explained  in  the  section,
              Recipient address specifications.

       flipr  Exchanges the Respond with the respond commands and vice-versa.

       forward-as-attachment
              Original  messages  are  normally sent as inline text with the forward command, and
              only the first part of a multipart message is included.  With this option, messages
              are  sent  as MIME message/rfc822 attachments, and all of their parts are included.
              The fwdignore and fwdretain options  are  ignored  when  the  forward-as-attachment
              option is set.

       fullnames
              When  replying  to  a  message,  mailx  normally removes the comment parts of email
              addresses, which by convention contain the full names of the recipients.   If  this
              variable is set, such stripping is not performed, and comments are retained.

       header Causes  the  header summary to be written at startup and after commands that affect
              the number of messages or the order of messages in the current folder;  enabled  by
              default.

       hold   This option is used to hold messages in the system mailbox by default.

       ignore Causes interrupt signals from the terminal to be ignored and echoed as @'s.

       ignoreeof
              An option related to dot is ignoreeof which makes mailx refuse to accept a control-
              d as the end of a message.  Ignoreeof also applies to mailx command mode.

       imap-use-starttls
              Causes mailx to issue a STARTTLS  command  to  make  an  unencrypted  IMAP  session
              SSL/TLS  encrypted.  This functionality is not supported by all servers, and is not
              used if the session is already encrypted by the IMAPS method.

       imap-use-starttls-user@host
              Activates imap-use-starttls for a specific account.

       keep   This option causes mailx to truncate the user's system mailbox instead of  deleting
              it  when it is empty.  This should always be set, since it prevents malicious users
              from creating fake mail folders in a world-writable spool directory.

       keepsave
              When a message is saved, it is usually discarded from the originating  folder  when
              mailx is quit.  Setting this option causes all saved message to be retained.

       markanswered
              When  a message is replied to and this variable is set, it is marked as having been
              answered.  This mark has no technical meaning in the mail system;  it  just  causes
              messages to be marked in the header summary, and makes them specially addressable.

       metoo  Usually,  when  a group is expanded that contains the sender, the sender is removed
              from the expansion.  Setting this option causes the sender to be  included  in  the
              group.

       newmail
              Checks  for  new  mail  in the current folder each time the prompt is printed.  For
              IMAP mailboxes, the server is then polled for new mail, which may result in delayed
              operation  if  the  connection to the server is slow.  A maildir folder must be re-
              scanned to determine if new mail has arrived.

              If this variable is set to the special value nopoll, an IMAP server is not actively
              asked for new mail, but new mail may still be detected and announced with any other
              IMAP command that is sent to the server.  A maildir folder is not scanned then.

              In any case, the IMAP server may send notifications about messages that  have  been
              deleted on the server by another process or client.  In this case, `Expunged n mes-
              sages' is printed regardless  of  this  variable,  and  message  numbers  may  have
              changed.

       noheader
              Setting the option noheader is the same as giving the -N flag on the command line.

       outfolder
              Causes the filename given in the record variable and the sender-based filenames for
              the Copy and Save commands to be interpreted relative to the directory given in the
              folder variable rather than to the current directory unless it is an absolute path-
              name.

       page   If set, each message the pipe command prints out is followed by a formfeed  charac-
              ter.

       piperaw
              Send messages to the pipe command without performing MIME and character set conver-
              sions.

       pop3-use-apop
              If this variable is set, the APOP authentication method is used when  a  connection
              to  a  POP3  server  is  initiated.   The  advantage  of this method over the usual
              USER/PASS authentication is that the password is not sent over the network in clear
              text.  The connection fails if the server does not support the APOP command.

       pop3-use-apop-user@host
              Enables pop3-use-apop for a specific account.

       pop3-use-starttls
              Causes  mailx  to  issue a STLS command to make an unencrypted POP3 session SSL/TLS
              encrypted.  This functionality is not supported by all servers, and is not used  if
              the session is already encrypted by the POP3S method.

       pop3-use-starttls-user@host
              Activates pop3-use-starttls for a specific account.

       print-all-chars
              This option causes all characters to be considered printable.  It is only effective
              if given in a startup file.  With this option set, some character sequences in mes-
              sages  may  put  the  user's terminal in an undefined state when printed; it should
              only be used as a last resort if no working system locale can be found.

       print-alternatives
              When a MIME message part of type multipart/alternative is displayed and it contains
              a  subpart  of  type  text/plain, other parts are normally discarded.  Setting this
              variable causes all subparts to be displayed, just as if the surrounding  part  was
              of type multipart/mixed.

       quiet  Suppresses the printing of the version when first invoked.

       record-resent
              If  both  this variable and the record variable are set, the resend and Resend com-
              mands save messages to the record folder as it is normally only done for newly com-
              posed messages.

       reply-in-same-charset
              If  this  variable  is  set, mailx first tries to use the same character set of the
              original message for replies.  If this fails, the sendcharsets variable  is  evalu-
              ated as usual.

       Replyall
              Reverses the sense of reply and Reply commands.

       save   When  the user aborts a message with two RUBOUT (interrupt characters) mailx copies
              the partial letter to the file `dead.letter' in the home directory.  This option is
              set by default.

       searchheaders
              If this option is set, then a message-list specifier in the form `/x:y' will expand
              to all messages containing the substring `y' in the header field `x'.   The  string
              search is case insensitive.

       sendwait
              When  sending  a message, wait until the mail transfer agent exits before accepting
              further commands.  If the mail transfer agent returns a non-zero exit  status,  the
              exit status of mailx will also be non-zero.

       showlast
              Setting  this option causes mailx to start at the last message instead of the first
              one when opening a mail folder.

       showname
              Causes mailx to use the sender's real name instead of  the  plain  address  in  the
              header field summary and in message specifications.

       showto Causes  the  recipient of the message to be shown in the header summary if the mes-
              sage was sent by the user.

       skipemptybody
              If an outgoing message does not contain any text in its first or only message part,
              do not send it but discard it silently (see also the -E option).

       smime-force-encryption
              Causes mailx to refuse sending unencrypted messages.

       smime-sign
              If  this  variable is set, outgoing messages are S/MIME signed with the user's pri-
              vate key.  Signing a message enables a recipient to verify that the sender  used  a
              valid  certificate,  that the email addresses in the certificate match those in the
              message header, and that the message content has not been  altered.   It  does  not
              change the message text, and people will be able to read the message as usual.

       smime-no-default-ca
              Do  not  load the default CA locations when verifying S/MIME signed messages.  Only
              applicable if S/MIME support is built using OpenSSL.

       smtp-use-starttls
              Causes mailx to issue a STARTTLS command to make an SMTP session SSL/TLS encrypted.
              Not  all servers support this command; because of common implementation defects, it
              cannot be automatically determined whether a server supports it or not.

       ssl-no-default-ca
              Do not load the default CA locations to verify SSL/TLS server  certificates.   Only
              applicable if SSL/TLS support is built using OpenSSL.

       ssl-v2-allow
              Accept  SSLv2  connections.   These  are normally not allowed because this protocol
              version is insecure.

       stealthmua
              Inhibits the generation of the `Message-Id:' and `User-Agent:' header  fields  that
              include  obvious references to mailx.  There are two pitfalls associated with this:
              First, the message id of outgoing messages is not known anymore.  Second, an expert
              may still use the remaining information in the header to track down the originating
              mail user agent.

       verbose
              Setting the option verbose is the same as using the -v flag on  the  command  line.
              When  mailx runs in verbose mode, details of the actual message delivery and proto-
              col conversations for IMAP, POP3, and SMTP, as well as of other internal processes,
              are  displayed  on the user's terminal, This is sometimes useful to debug problems.
              Mailx prints all data that is sent to remote  servers  in  clear  texts,  including
              passwords,  so care should be taken that no unauthorized option can view the screen
              if this option is enabled.

       writebackedited
              If this variable is set, messages modified using the edit or  visual  commands  are
              written  back  to  the  current  folder when it is quit.  This is only possible for
              writable folders in mbox format.  Setting this variable also disables MIME decoding
              and decryption for the editing commands.

   String Options
       The string options include the following:

       attrlist
              A  sequence  of  characters to print in the `attribute' column of a header summary,
              each for one type of messages in the following order: new, unread but old, new  but
              read,  read  and  old,  saved, preserved, mboxed, flagged, answered, draft, killed,
              start of a collapsed  thread,  collapsed,  classified  as  junk.   The  default  is
              `NUROSPMFATK+-J', or `NU  *HMFATK+-J' if bsdflags or the SYSV3 environment variable
              are set.

       autobcc
              Specifies a list of recipients to which a blind carbon copy of each  outgoing  mes-
              sage will be sent automatically.

       autocc Specifies a list of recipients to which a carbon copy of each outgoing message will
              be sent automatically.

       autosort
              Causes sorted mode (see the sort command) to  be  entered  automatically  with  the
              value of this option as sorting method when a folder is opened.

       cmd    The default value for the pipe command.

       crt    The  valued  option crt is used as a threshold to determine how long a message must
              be before PAGER is used to read it.  If crt is set without a value, then the height
              of  the  terminal screen stored in the system is used to compute the threshold (see
              stty(1)).

       DEAD   The name of the file  to  use  for  saving  aborted  messages.   This  defaults  to
              `dead.letter' in the user's home directory.

       EDITOR Pathname  of  the  text  editor  to  use in the edit command and ~e escape.  If not
              defined, then a default editor is used.

       encoding
              The default MIME encoding to use in  outgoing  text  messages  and  message  parts.
              Valid  values are 8bit or quoted-printable.  The default is 8bit.  In case the mail
              transfer system is not ESMTP compliant, quoted-printable should  be  used  instead.
              If there is no need to encode a message, 7bit transfer mode is used, without regard
              to the value of this variable.  Binary data is always encoded in base64 mode.

       escape If defined, the first character of this option gives the character to  use  in  the
              place of ~ to denote escapes.

       folder The name of the directory to use for storing folders of messages.  All folder names
              that begin with `+' refer to files below that directory.   If  the  directory  name
              begins  with  a  `/', mailx considers it to be an absolute pathname; otherwise, the
              folder directory is found relative to the user's home directory.

              The directory name may also refer to an IMAP account; any names that begin with `+'
              then  refer to IMAP mailboxes on that account.  An IMAP folder is normally given in
              the form

                  imaps://mylogin AT imap.example

              In this case, the `+' and `@' prefixes for folder names have the same  effect  (see
              the folder command).

              Some  IMAP  servers  do not accept the creation of mailboxes in the hierarchy base;
              they require that they are created as subfolders of `INBOX'.  With such servers,  a
              folder name of the form

                  imaps://mylogin AT imap.example/INBOX.

              should  be  used  (the last character is the server's hierarchy delimiter).  Folder
              names prefixed by `+' will then refer to folders below `INBOX', while folder  names
              prefixed  by `@' refer to folders below the hierarchy base.  See the imap namespace
              command for a method to detect the appropriate prefix and delimiter.

       folder-hook
              When a folder is opened and this variable is set, the macro  corresponding  to  the
              value  of  this  variable  is  executed.   The  macro is also invoked when new mail
              arrives, but message lists for commands executed from the macro only include  newly
              arrived messages then.

       folder-hook-fullname
              When  a  folder  named  fullname is opened, the macro corresponding to the value of
              this variable is executed.  Unlike other folder specifications, the fully  expanded
              name  of a folder, without metacharacters, is used to avoid ambiguities.  The macro
              specified with folder-hook is not executed if this  variable  is  effective  for  a
              folder (unless it is explicitly invoked within the called macro).

       from   The  address  (or a list of addresses) to put into the `From:' field of the message
              header.  If replying to a message, these addresses are handled as if they  were  in
              the  alternates  list.  If the machine's hostname is not valid at the Internet (for
              example at a dialup machine), either this variable or hostname have to  be  set  to
              get  correct Message-ID header fields.  If from contains more than one address, the
              sender variable must also be set.

       fwdheading
              The string to print before the text of a message with the forward  command  (unless
              the  forward-as-attachment  variable is set).  Defaults to ``-------- Original Mes-
              sage --------'' if unset.  If it is set to the empty string, no heading is printed.

       headline
              A format string to use for the header summary, similar to printf  formats.   A  `%'
              character introduces a format specifier.  It may be followed by a number indicating
              the field width.  If the field is a number, the width may be negative, which  indi-
              cates that it is to be left-aligned.  Valid format specifiers are:


                  %a    Message attributes.
                  %c    The score of the message.
                  %d    The date when the message was received.
                  %e    The indenting level in threaded mode.
                  %f    The address of the message sender.
                  %i    The message thread structure.
                  %l    The number of lines of the message.
                  %m    Message number.
                  %o    The number of octets (bytes) in the message.
                  %s    Message subject (if any).
                  %S    Message subject (if any) in double quotes.
                  %t    The position in threaded/sorted order.
                  %>    A `>' for the current message, otherwise ` '.
                  %<    A `<' for the current message, otherwise ` '.
                  %%    A `%' character.

              The         default         is         `%>%a%m %18f %16d %4l/%-5o %i%s',         or
              `%>%a%m %20f  %16d %3l/%-5o %i%S' if bsdcompat is set.

       hostname
              Use this string as hostname when expanding local addresses  instead  of  the  value
              obtained from uname(2) and getaddrinfo(3).

       imap-auth
              Sets  the IMAP authentication method.  Valid values are `login' for the usual pass-
              word-based authentication (the default),  `cram-md5',  which  is  a  password-based
              authentication  that does not send the password over the network in clear text, and
              `gssapi' for GSSAPI-based authentication.

       imap-auth-user@host
              Sets the IMAP authentication method for a specific account.

       imap-cache
              Enables caching of IMAP mailboxes.  The value of this  variable  must  point  to  a
              directory  that is either existent or can be created by mailx.  All contents of the
              cache can be deleted by mailx at any time; it is not safe to make assumptions about
              them.

       imap-keepalive
              IMAP  servers  may  close the connection after a period of inactivity; the standard
              requires this to be at least 30 minutes, but practical experience may  vary.   Set-
              ting  this  variable  to a numeric value greater than 0 causes a NOOP command to be
              sent each value seconds if no other operation is performed.

       imap-list-depth
              When retrieving the list of folders on an IMAP server, the  folders  command  stops
              after  it  has reached a certain depth to avoid possible infinite loops.  The value
              of this variable sets the maximum depth allowed.  The default is 2.  If the  folder
              separator  on  the current IMAP server is a slash `/', this variable has no effect,
              and the folders command does not descend to subfolders.

       indentprefix
              String used by the `~m' and `~M' tilde escapes and by the quote option for  indent-
              ing  messages,  in  place  of  the normal tab character (^I).  Be sure to quote the
              value if it contains spaces or tabs.

       junkdb The location of the junk mail database.  The string is treated like a folder  name,
              as described for the folder command.

              The  files  in the junk mail database are normally stored in compress(1) format for
              saving space.  If processing time is considered more important,  uncompress(1)  can
              be  used  to store them in plain form.  Mailx will then work using the uncompressed
              files.

       LISTER Pathname of the directory lister to use in the folders command  when  operating  on
              local mailboxes.  Default is /bin/ls.

       MAIL   Is  used  as  the user's mailbox, if set.  Otherwise, a system-dependent default is
              used.  Can be a protocol:// string (see the folder command for more information).

       MAILX_HEAD
              A string to put at the beginning of each new message.  The  escape  sequences  `\t'
              (tabulator) and `\n' (newline) are understood.

       MAILX_TAIL
              A string to put at the end of each new message.  The escape sequences `\t' (tabula-
              tor) and `\n' (newline) are understood.

       maximum-unencoded-line-length
              Messages that contain lines longer than the value of this variable are  encoded  in
              quoted-printable even if they contain only ASCII characters.  The maximum effective
              value is 950.  If set to 0, all ASCII text messages are  encoded  in  quoted-print-
              able.   S/MIME signed messages are always encoded in quoted-printable regardless of
              the value of this variable.

       MBOX   The name of the mbox file.  It can be the name of a folder.  The default is  `mbox'
              in the user's home directory.

       NAIL_EXTRA_RC
              The  name of an optional startup file to be read after ~/.mailrc.  This variable is
              ignored if it is imported from the environment; it has an effect only if it is  set
              in  /etc/mail.rc  or  ~/.mailrc  to  allow  bypassing  the configuration with e. g.
              `MAILRC=/dev/null'.  Use this file for commands that are not  understood  by  other
              mailx implementations.

       newfolders
              If  this  variable  has  the  value maildir, newly created local folders will be in
              maildir format.

       nss-config-dir
              A directory that contains the files certN.db to retrieve certificates,  keyN.db  to
              retrieve  private keys, and secmod.db, where N is a digit.  These are usually taken
              from Mozilla installations, so an  appropriate  value  might  be  `~/.mozilla/fire-
              fox/default.clm'.   Mailx  opens  these  files  read-only and does not modify them.
              However, if the files are modified by Mozilla while mailx is running, it will print
              a `Bad database' message.  It may be necessary to create copies of these files that
              are exclusively used by mailx then.  Only applicable if S/MIME and SSL/TLS  support
              is built using Network Security Services (NSS).

       ORGANIZATION
              The value to put into the `Organization:' field of the message header.

       PAGER  Pathname  of  the  program  to use in the more command or when crt variable is set.
              The default paginator pg(1) or, in BSD compatibility mode, more(1) is used if  this
              option is not defined.

       password-user@host
              Set  the password for user when connecting to host.  If no such variable is defined
              for a host, the user will be asked for a password on  standard  input.   Specifying
              passwords  in a startup file is generally a security risk, the file should be read-
              able by the invoking user only.

       pipe-content/subcontent
              When a MIME message part of content/subcontent type is displayed or it  is  replied
              to,  its text is filtered through the value of this variable interpreted as a shell
              command.  Special care must be taken when using such commands as mail  viruses  may
              be  distributed  by this method; if messages of type application/x-sh were filtered
              through the shell, for example, a message sender  could  easily  execute  arbitrary
              code on the system mailx is running on.

       pop3-keepalive
              POP3  servers  may  close the connection after a period of inactivity; the standard
              requires this to be at least 10 minutes, but practical experience may  vary.   Set-
              ting  this  variable  to a numeric value greater than 0 causes a NOOP command to be
              sent each value seconds if no other operation is performed.

       prompt The string printed when a command is accepted.  Defaults to `? ', or to `& ' if the
              bsdcompat variable is set.

       quote  If  set,  mailx starts a replying message with the original message prefixed by the
              value of the variable indentprefix.  Normally, a heading consisting of `Fromheader-
              field wrote:' is printed before the quotation.  If the string noheading is assigned
              to the quote variable, this heading is omitted.  If the string headers is assigned,
              the  headers  selected  by the ignore/retain commands are printed above the message
              body, thus quote acts like an automatic ~m command then.  If the string  allheaders
              is assigned, all headers are printed above the message body, and all MIME parts are
              included, thus quote acts like an automatic ~M command then.

       record If defined, gives the pathname of the folder used to record all outgoing mail.   If
              not defined, then outgoing mail is not so saved.  When saving to this folder fails,
              the message is not sent but saved to the `dead.letter' file instead.

       replyto
              A list of addresses to put into the `Reply-To:' field of the  message  header.   If
              replying to a message, such addresses are handled as if they were in the alternates
              list.

       screen When mailx initially prints the message headers, it determines the number to  print
              by  looking  at  the  speed  of the terminal.  The faster the terminal, the more it
              prints.  This option overrides this calculation  and  specifies  how  many  message
              headers are printed.  This number is also used for scrolling with the z command.

       sendcharsets
              A  comma-separated  list  of character set names that can be used in Internet mail.
              When a message that contains characters not representable in US-ASCII  is  prepared
              for sending, mailx tries to convert its text to each of the given character sets in
              order and uses the first appropriate one.  The default is `utf-8'.

              Character sets assigned to this variable should be ordered in ascending complexity.
              That is, the list should start with e.g.  `iso-8859-1' for compatibility with older
              mail clients, might contain some other language-specific character sets, and should
              end with `utf-8' to handle messages that combine texts in multiple languages.

       sender An  address  that is put into the `Sender:' field of outgoing messages.  This field
              needs not normally be present.  It is, however, required if the `From:' field  con-
              tains  more  than  one address.  It can also be used to indicate that a message was
              sent on behalf of somebody other; in this case, `From:' should contain the  address
              of  the  person that took responsibility for the message, and `Sender:' should con-
              tain the address of the person that actually sent the message.  The sender  address
              is handled as if it were in the alternates list.

       sendmail
              To  use  an alternate mail delivery system, set this option to the full pathname of
              the program to use.  This should be used with care.

       SHELL  Pathname of the shell to use in the ! command and the ~! escape.  A  default  shell
              is used if this option is not defined.


       Sign   A string for use with the ~A command.

       sign   A string for use with the ~a command.

       signature
              Must  correspond  to the name of a readable file if set.  The file's content
              is then appended to each singlepart message and to the first  part  of  each
              multipart  message.  Be warned that there is no possibility to edit the sig-
              nature for an individual message.

       smime-ca-dir
              Specifies a directory with CA certificates for verification of S/MIME signed
              messages.   The format is the same as described in SSL_CTX_load_verify_loca-
              tions(3).  Only applicable if S/MIME support is built using OpenSSL.

       smime-ca-file
              Specifies a file with CA certificates for verification of S/MIME signed mes-
              sages.   The  format  is  the same as described in SSL_CTX_load_verify_loca-
              tions(3).  Only applicable if S/MIME support is built using OpenSSL.

       smime-cipher-user@host
              Specifies a cipher to use when  generating  S/MIME  encrypted  messages  for
              user@host.  Valid ciphers are rc2-40 (RC2 with 40 bits), rc2-64 (RC2 with 64
              bits), des (DES, 56 bits) and des-ede3 (3DES, 112/168 bits).  The default is
              3DES.   It  is not recommended to use the other ciphers unless a recipient's
              client is actually unable to handle 3DES since they are comparatively  weak;
              but even so, the recipient should upgrade his software in preference.

       smime-crl-file
              Specifies  a  file  that  contains a CRL in PEM format to use when verifying
              S/MIME messages.  Only applicable if S/MIME support is built using OpenSSL.

       smime-crl-dir
              Specifies a directory that contains files with CRLs in  PEM  format  to  use
              when  verifying S/MIME messages.  Only applicable if S/MIME support is built
              using OpenSSL.

       smime-encrypt-user@host
              If this variable is set, messages to user@host are encrypted before sending.
              If  S/MIME support is built using OpenSSL, the value of the variable must be
              set to the name of a file that contains a certificate  in  PEM  format.   If
              S/MIME  support  is  built using NSS, the value of this variable is ignored,
              but if multiple certificates for user@host are  available,  the  smime-nick-
              name-user@host  variable  should  be  set.   Otherwise a certificate for the
              recipient is automatically retrieved from the certificate database, if  pos-
              sible.

              If  a message is sent to multiple recipients, each of them for whom a corre-
              sponding variable is set will receive  an  individually  encrypted  message;
              other  recipients  will continue to receive the message in plain text unless
              the smime-force-encryption variable is  set.   It  is  recommended  to  sign
              encrypted messages, i.e. to also set the smime-sign variable.

       smime-nickname-user@host
              Specifies  the nickname of a certificate to be used when encrypting messages
              for user@host .  Only applicable if S/MIME support is built using NSS.

       smime-sign-cert
              Points to a file in PEM format that contains the user's private key as  well
              as  his  certificate.   Both are used with S/MIME for signing and decrypting
              messages.  Only applicable if S/MIME support is built using OpenSSL.

       smime-sign-cert-user@host
              Overrides smime-sign-cert for the specific addresses.  When signing messages
              and the value of the from variable is set to user@host, the specific file is
              used.  When decrypting messages, their recipient fields (To:  and  Cc:)  are
              searched  for addresses for which such a variable is set.  Mailx always uses
              the first address that matches, so if the same message is sent to more  than
              one  of  the  user's  addresses  using different encryption keys, decryption
              might fail.  Only applicable if S/MIME support is built using OpenSSL.

       smime-sign-nickname
              Specifies that the named certificate be used  for  signing  mail.   If  this
              variable  is  not  set,  but  a single certificate matching the current from
              address is found in the database, that  one  is  used  automatically.   Only
              applicable if S/MIME support is built using NSS.

       smime-sign-nickname-user@host
              Overrides  smime-sign-nickname  for  a specific address.  Only applicable if
              S/MIME support is built using NSS.

       smtp   Normally, mailx invokes sendmail(8) directly to transfer messages.   If  the
              smtp variable is set, a SMTP connection to the server specified by the value
              of this variable is used instead.  If the SMTP server does not use the stan-
              dard  port, a value of server:port can be given, with port as a name or as a
              number.

              There are two possible methods  to  get  SSL/TLS  encrypted  SMTP  sessions:
              First,  the  STARTTLS  command can be used to encrypt a session after it has
              been initiated,  but  before  any  user-related  data  has  been  sent;  see
              smtp-use-starttls  above.   Second,  some  servers  accept sessions that are
              encrypted from their beginning on. This  mode  is  configured  by  assigning
              smtps://server[:port] to the smtp variable.

              The SMTP transfer is executed in a child process; unless either the sendwait
              or the verbose variable is set, this process  runs  asynchronously.   If  it
              receives a TERM signal, it will abort and save the message to the `dead.let-
              ter' file.

       smtp-auth
              Sets the SMTP authentication method.  If set to `login',  or  if  unset  and
              smtp-auth-user is set, AUTH LOGIN is used.  If set to `cram-md5', AUTH CRAM-
              MD5 is used; if set to `plain', AUTH PLAIN  is  used.   Otherwise,  no  SMTP
              authentication is performed.

       smtp-auth-user@host
              Overrides  smtp-auth  for  specific values of sender addresses, depending on
              the from variable.

       smtp-auth-password
              Sets the global password for SMTP AUTH.  Both user and password have  to  be
              given for AUTH LOGIN and AUTH CRAM-MD5.

       smtp-auth-password-user@host
              Overrides  smtp-auth-password  for  specific  values  of  sender  addresses,
              depending on the from variable.

       smtp-auth-user
              Sets the global user name for SMTP AUTH.  Both user and password have to  be
              given for AUTH LOGIN and AUTH CRAM-MD5.

              If  this  variable is set but neither smtp-auth-password or a matching smtp-
              auth-password-user@host can be found, mailx will as for a  password  on  the
              user's terminal.

       smtp-auth-user-user@host
              Overrides  smtp-auth-user for specific values of sender addresses, depending
              on the from variable.

       ssl-ca-dir
              Specifies a directory with  CA  certificates  for  verification  of  SSL/TLS
              server certificates.  See SSL_CTX_load_verify_locations(3) for more informa-
              tion.  Only applicable if SSL/TLS support is built using OpenSSL.

       ssl-ca-file
              Specifies a file with CA certificates for  verification  of  SSL/TLS  server
              certificates.   See  SSL_CTX_load_verify_locations(3)  for more information.
              Only applicable if SSL/TLS support is built using OpenSSL.

       ssl-cert
              Sets the file name  for  a  SSL/TLS  client  certificate  required  by  some
              servers.  Only applicable if SSL/TLS support is built using OpenSSL.

       ssl-cert-user@host
              Sets an account-specific file name for a SSL/TLS client certificate required
              by some servers.  Overrides ssl-cert for the specified account.  Only appli-
              cable if SSL/TLS support is built using OpenSSL.

       ssl-cipher-list
              Specifies  a  list  of  ciphers for SSL/TLS connections.  See ciphers(1) for
              more information.   Only  applicable  if  SSL/TLS  support  is  built  using
              OpenSSL.

       ssl-crl-file
              Specifies  a  file  that  contains a CRL in PEM format to use when verifying
              SSL/TLS server certificates.  Only applicable if SSL/TLS  support  is  built
              using OpenSSL.

       ssl-crl-dir
              Specifies  a  directory  that  contains files with CRLs in PEM format to use
              when verifying SSL/TLS server certificates.  Only applicable if SSL/TLS sup-
              port is built using OpenSSL.

       ssl-key
              Sets  the file name for the private key of a SSL/TLS client certificate.  If
              unset, the name of the certificate file is used.  The file is expected to be
              in PEM format.  Only applicable if SSL/TLS support is built using OpenSSL.

       ssl-key-user@host
              Sets  an  account-specific file name for the private key of a SSL/TLS client
              certificate.  Overrides ssl-key for the specified account.  Only  applicable
              if SSL/TLS support is built using OpenSSL.

       ssl-method
              Selects  a  SSL/TLS  protocol  version; valid values are `ssl2', `ssl3', and
              `tls1'.  If unset, the method is selected automatically, if possible.

       ssl-method-user@host
              Overrides ssl-method for a specific account.

       ssl-rand-egd
              Gives the pathname to an entropy daemon socket, see RAND_egd(3).

       ssl-rand-file
              Gives the pathname to a file with entropy data, see  RAND_load_file(3).   If
              the  file is a regular file writable by the invoking user, new data is writ-
              ten to it after it has been loaded.  Only applicable if SSL/TLS  support  is
              built using OpenSSL.

       ssl-verify
              Sets  the  action  to  be performed if an error occurs during SSL/TLS server
              certificate validation.  Valid values are `strict' (fail and  close  connec-
              tion immediately), `ask' (ask whether to continue on standard input), `warn'
              (print a warning and continue), `ignore' (do not perform  validation).   The
              default is `ask'.

       ssl-verify-user@host
              Overrides ssl-verify for a specific account.

       toplines
              If  defined,  gives  the number of lines of a message to be printed out with
              the top command; normally, the first five lines are printed.

       ttycharset
              The character set of the terminal mailx operates on.  There is  normally  no
              need  to  set  this variable since mailx can determine this automatically by
              looking at the LC_CTYPE locale setting;  if  this  succeeds,  the  value  is
              assigned  at  startup  and  will be displayed by the set command.  Note that
              this is not necessarily a character set name that can be  used  in  Internet
              messages.

       VISUAL Pathname of the text editor to use in the visual command and ~v escape.

ENVIRONMENT VARIABLES
       Besides  the  variables  described  above,  mailx  uses  the  following environment
       strings:

       HOME   The user's home directory.

       LANG, LC_ALL, LC_COLLATE, LC_CTYPE, LC_MESSAGES
              See locale(7).

       MAILRC Is used as startup file instead of ~/.mailrc if set.  When mailx scripts are
              invoked on behalf of other users, this variable should be set to `/dev/null'
              to avoid side-effects from reading their configuration files.

       NAILRC If this variable is set and MAILRC is not set, it is read as startup file.

       SYSV3  Changes the letters printed in the first column of a header summary.

       TMPDIR Used as directory for temporary files instead of /tmp, if set.

FILES
       ~/.mailrc
              File giving initial commands.

       /etc/mail.rc
              System wide initialization file.

       ~/.mime.types
              Personal MIME types.

       /etc/mime.types
              System wide MIME types.

EXAMPLES
   Getting started
       The mailx command has two distinct usages, according to whether one wants  to  send
       or  receive  mail.  Sending mail is simple: to send a message to a user whose email
       address is, say, <bill AT host.example>, use the shell command:

           $ mailx bill AT host.example

       then type your message.  Mailx will prompt you for a message subject  first;  after
       that,  lines  typed by you form the body of the message.  When you reach the end of
       the message, type an EOT (control-d) at the beginning of a line, which  will  cause
       mailx to echo `EOT' and return you to the shell.

       If,  while you are composing the message you decide that you do not wish to send it
       after all, you can abort the letter with a RUBOUT.  Typing a single  RUBOUT  causes
       mailx  to  print  `(Interrupt -- one more to kill letter)'.  Typing a second RUBOUT
       causes mailx to save your partial letter on the file  `dead.letter'  in  your  home
       directory  and  abort  the letter.  Once you have sent mail to someone, there is no
       way to undo the act, so be careful.

       If you want to send the same message to several other people, you  can  list  their
       email addresses on the command line.  Thus,

           $ mailx sam AT workstation.example bob AT server.example
           Subject: Fees
           Tuition fees are due next Friday.  Don't forget!
           <Control-d>
           EOT
           $

       will send the reminder to <sam AT workstation.example>.  and <bob AT server.example>.

       To read your mail, simply type

           $ mailx

       Mailx  will respond by typing its version number and date and then listing the mes-
       sages you have waiting.  Then it will type a prompt and await  your  command.   The
       messages are assigned numbers starting with 1--you refer to the messages with these
       numbers.  Mailx keeps track of which messages are new (have  been  sent  since  you
       last read your mail) and read (have been read by you).  New messages have an N next
       to them in the header listing and old, but unread messages have a U next  to  them.
       Mailx  keeps  track  of  new/old and read/unread messages by putting a header field
       called Status into your messages.

       To look at a specific message, use the type command, which may  be  abbreviated  to
       simply t .  For example, if you had the following messages:

           O 1 drfoo AT myhost.example Wed Sep  1 19:52  18/631 "Fees"
           O 2 sam AT friends.example  Thu Sep  2 00:08  30/895

       you could examine the first message by giving the command:

           type 1

       which might cause mailx to respond with, for example:

           Message  1:
           From drfoo AT myhost.example Wed Sep  1 19:52:25 2004
           Subject: Fees
           Status: R

           Tuition fees are due next Wednesday.  Don't forget!


       Many  mailx  commands that operate on messages take a message number as an argument
       like the type command.  For these commands, there is a notion of a current message.
       When  you  enter  the mailx program, the current message is initially the first (or
       the first recent) one.  Thus, you can often omit the message number  and  use,  for
       example,

           t

       to  type  the  current  message.  As a further shorthand, you can type a message by
       simply giving its message number.  Hence,

           1

       would type the first message.

       Frequently, it is useful to read the messages in your mailbox in order,  one  after
       another.   You can read the next message in mailx by simply typing a newline.  As a
       special case, you can type a newline as your first command to  mailx  to  type  the
       first message.

       If,  after  typing  a  message, you wish to immediately send a reply, you can do so
       with the reply command.  This command, like type, takes  a  message  number  as  an
       argument.   mailx then begins a message addressed to the user who sent you the mes-
       sage.  You may then type in your letter in reply, followed by a <control-d> at  the
       beginning of a line, as before.

       Note  that mailx copies the subject header from the original message.  This is use-
       ful in that correspondence about a particular matter will tend to retain  the  same
       subject  heading, making it easy to recognize.  If there are other header fields in
       the message, like `Cc:', the information found will also be used.

       Sometimes you will receive a message that has been sent to several people and  wish
       to  reply only to the person who sent it.  Reply with a capital R replies to a mes-
       sage, but sends a copy to the sender only.

       If you wish, while reading your mail, to send a message to someone, but  not  as  a
       reply to one of your messages, you can send the message directly with the mail com-
       mand, which takes as arguments the names of the recipients you  wish  to  send  to.
       For example, to send a message to <frank AT machine.example>, you would do:

           mail frank AT machine.example

       To delete a message from the mail folder, you can use the delete command.  In addi-
       tion to not saving deleted messages, mailx will not let you type them, either.  The
       effect is to make the message disappear altogether, along with its number.

       Many  features  of  mailx can be tailored to your liking with the set command.  The
       set command has two forms, depending on whether you are setting a binary option  or
       a  valued  option.   Binary  options  are either on or off.  For example, the askcc
       option informs mailx that each time you send a message, you want it to  prompt  you
       for  a  `Cc:'  header, to be included in the message.  To set the askcc option, you
       would type

           set askcc

       Valued options are values which mailx uses to adapt to your tastes.   For  example,
       the  record option tells mailx where to save messages sent by you, and is specified
       by

           set record=Sent

       for example.  Note that no spaces are allowed in set record=Sent .

       Mailx includes a simple facility for maintaining groups  of  messages  together  in
       folders.   To  use  the folder facility, you must tell mailx where you wish to keep
       your folders.  Each folder of messages will be a single file.  For convenience, all
       of  your  folders  are  kept in a single directory of your choosing.  To tell mailx
       where your folder directory is, put a line of the form

           set folder=letters

       in your .mailrc file.  If, as in the example above, your folder directory does  not
       begin  with  a  `/',  mailx  will  assume that your folder directory is to be found
       starting from your home directory.

       Anywhere a file name is expected, you can use a folder  name,  preceded  with  `+'.
       For example, to put a message into a folder with the save command, you can use:

           save +classwork

       to  save the current message in the classwork folder.  If the classwork folder does
       not yet exist, it will be created.  Note that messages which  are  saved  with  the
       save command are automatically removed from your system mailbox.

       In order to make a copy of a message in a folder without causing that message to be
       removed from your system mailbox, use the copy command, which is identical  in  all
       other respects to the save command.

       The  folder  command  can  be  used  to direct mailx to the contents of a different
       folder.  For example,

           folder +classwork

       directs mailx to read the contents of the classwork folder.  All  of  the  commands
       that  you  can use on your system mailbox are also applicable to folders, including
       type, delete, and reply.  To inquire which folder you are  currently  editing,  use
       simply:

           folder

       To list your current set of folders, use the folders command.

       Finally,  the  help  command  is available to print out a brief summary of the most
       important mailx commands.

       While typing in a message to be sent to others, it is often useful to  be  able  to
       invoke  the  text editor on the partial message, print the message, execute a shell
       command, or do some other auxiliary function.  Mailx  provides  these  capabilities
       through  tilde  escapes  , which consist of a tilde (~) at the beginning of a line,
       followed by a single character which indicates the function to be  performed.   For
       example, to print the text of the message so far, use:

           ~p

       which  will print a line of dashes, the recipients of your message, and the text of
       the message so far.  A list of the most important tilde escapes is  available  with
       `~?'.

   IMAP or POP3 client setup
       First  you need the following data from your ISP: the host name of the IMAP or POP3
       server, user name and password for this server, and a  notice  whether  the  server
       uses SSL/TLS encryption.  Assuming the host name is `server.myisp.example' and your
       user name for that server is `mylogin', you can refer to  this  account  using  the
       folder command or -f command line option with

           imaps://mylogin AT server.example

       (This  string  is not necessarily the same as your Internet mail address.)  You can
       replace `imaps://' with `imap://' if the server  does  not  support  SSL/TLS.   (If
       SSL/TLS  support is built using NSS, the nss-config-dir variable must be set before
       a connection can be initiated, see above).  Use  `pop3s://'  or  `pop3://'  if  the
       server  does not offer IMAP.  You should use IMAP if you can, though; first because
       it requires fewer network operations than POP3 to get the contents of  the  mailbox
       and  is  thus  faster;  and second because message attributes are maintained by the
       IMAP server, so you can easily distinguish new and old messages each time you  con-
       nect.   Even if the server does not accept IMAPS or POP3S connections, it is possi-
       ble that it supports the STARTTLS method to make a session SSL/TLS encrypted  after
       the  initial  connection has been performed, but before authentication begins.  The
       only reliable method to see if this works is to try it; enter one of

           set imap-use-starttls
           set pop3-use-starttls

       before you initiate the connection.

       As you probably want messages to be deleted from this account  after  saving  them,
       prefix  it  with  `%:'.  The shortcut command can be used to avoid typing that many
       characters every time you want to connect:

           shortcut myisp %:imaps://mylogin AT server.example

       You might want to put this string into a startup file.  As the shortcut command  is
       specific to this implementation of mailx and will confuse other implementations, it
       should not be used in ~/.mailrc, instead, put

           set NAIL_EXTRA_RC=~/.nailrc

       in ~/.mailrc and create a file ~/.nailrc containing  the  shortcut  command  above.
       You can then access your remote mailbox by invoking `mailx -f myisp' on the command
       line, or by executing `fi myisp' within mailx.

       If you want to use more than one IMAP mailbox on a server, or if you  want  to  use
       the IMAP server for mail storage too, the account command (which is also mailx-spe-
       cific) is more appropriate than the shortcut command.  You can put the following in
       ~/.nailrc:

           account myisp {
               set folder=imaps://mylogin AT server.example
               set record=+Sent MBOX=+mbox outfolder
           }

       and  can then access incoming mail for this account by invoking `mailx -A myisp' on
       the command line, or by executing `ac myisp' within mailx.  After that,  a  command
       like  `copy  1 +otherfolder' will refer to otherfolder on the IMAP server.  In par-
       ticular, `fi &' will change to the mbox folder,  and  `fi  +Sent'  will  show  your
       recorded sent mail, with both folders located on the IMAP server.

       Mailx will ask you for a password string each time you connect to a remote account.
       If you can reasonably trust the security of your workstation,  you  can  give  this
       password in the startup file as

           set password-mylogin AT server.example="SECRET"

       You should change the permissions of this file to 0600, see chmod(1).

       Mailx  supports  different  authentication methods for both IMAP and POP3.  If Ker-
       beros is used at your location, you can try to activate GSSAPI-based authentication
       by

           set imap-auth=gssapi

       The  advantage  of this method is that mailx does not need to know your password at
       all, nor needs to send sensitive data over the network.  Otherwise, the options

           set imap-auth=cram-md5
           set pop3-use-apop

       for IMAP and POP3, respectively, offer authentication methods that  avoid  to  send
       the  password  in  clear  text  over  the network, which is especially important if
       SSL/TLS cannot be used.  If the server does not offer any of  these  authentication
       methods, conventional user/password based authentication must be used.  It is some-
       times helpful to set the verbose option when authentication problems occur.   Mailx
       will  display  all  data  sent  to the server in clear text on the screen with this
       option, including passwords.  You should thus take care that no unauthorized person
       can look at your terminal when this option is set.

       If  you regularly use the same workstation to access IMAP accounts, you can greatly
       enhance performance by enabling local caching of IMAP messages.   For  any  message
       that  has been fully or partially fetched from the server, a local copy is made and
       is used when the message is accessed again, so most data is  transferred  over  the
       network once only.  To enable the IMAP cache, select a local directory name and put

           set imap-cache=~/localdirectory

       in the startup file.  All files within that directory can be overwritten or deleted
       by mailx at any time, so you should not use the directory to store  other  informa-
       tion.

       Once the cache contains some messages, it is not strictly necessary anymore to open
       a connection to the IMAP server to access them.  When mailx is invoked with the  -D
       option,  or when the disconnected variable is set, only cached data is used for any
       folder you open.  Messages that have not yet been completely cached are not  avail-
       able  then,  but  all other messages can be handled as usual.  Changes made to IMAP
       mailboxes in disconnected mode are committed to the IMAP server  next  time  it  is
       used  in online mode.  Synchronizing the local status with the status on the server
       is thus partially within your responsibility; if you forget to initiate  a  connec-
       tion  to the server again before you leave your location, changes made on one work-
       station are not available on others.  Also if you alter IMAP mailboxes from a work-
       station while uncommitted changes are still pending on another, the latter data may
       become invalid.  The same might also  happen  because  of  internal  server  status
       changes.   You  should  thus  carefully  evaluate  this feature in your environment
       before you rely on it.

       Many servers will close the connection after a short period of inactivity. Use  one
       of

           set pop3-keepalive=30
           set imap-keepalive=240

       to send a keepalive message each 30 seconds for POP3, or each 4 minutes for IMAP.

       If  you encounter problems connecting to a SSL/TLS server, try the ssl-rand-egd and
       ssl-rand-file variables (see the OpenSSL FAQ for more information) or  specify  the
       protocol  version  with ssl-method.  Contact your ISP if you need a client certifi-
       cate or if verification of the server certificate fails.  If the failed certificate
       is indeed valid, fetch its CA certificate by executing the shell command

           $ openssl s_client </dev/null -showcerts -connect \
                  server.myisp.example:imaps 2>&1 | tee log

       (see  s_client(1))  and  put it into the file specified with ssl-ca-file.  The data
       you need is located at the end of the certificate chain within (and including)  the
       `BEGIN  CERTIFICATE'  and  `END  CERTIFICATE'  lines.  (Note that it is possible to
       fetch a forged certificate by this method.  You can only  completely  rely  on  the
       authenticity  of  the  CA  certificate  if you fetch it in a way that is trusted by
       other means, such as by personally receiving the certificate on storage media.)

   Creating a score file or message filter
       The scoring commands are best separated from other configuration for  clarity,  and
       are  mostly  mailx specific.  It is thus recommended to put them in a separate file
       that is sourced from your NAIL_EXTRA_RC as follows:

           source ~/.scores

       The .scores file could then look as follows:

           define list {
               score (subject "important discussion") +10
               score (subject "annoying discussion") -10
               score (from "nicefellow@goodnet") +15
               score (from "badguy@poornet") -5
               move (header x-spam-flag "+++++") +junk
           }
           set folder-hook-imap://user@host/public.list=list

       In this scheme, you would see any mail from `nicefellow@goodnet', even if the  sur-
       rounding  discussion  is  annoying;  but  you  normally  would  not  see  mail from
       `badguy@poornet', unless he participates in  the  important  discussion.   Messages
       that  are  marked  with  five  or more plus characters in their `X-Spam-Flag' field
       (inserted by some server-side filtering software) are moved to the folder `junk' in
       the folder directory.

       Be aware that all criteria in () lead to substring matches, so you would also score
       messages from e.g. `notsobadguy@poornetmakers' negative here.  It  is  possible  to
       select  addresses  exactly using "address" message specifications, but these cannot
       be executed remotely and will thus cause all headers to  be  downloaded  from  IMAP
       servers while looking for matches.

       When  searching messages on an IMAP server, best performance is usually achieved by
       sending as many criteria as possible in one large ()  specification,  because  each
       single such specification will result in a separate network operation.

   Activating the Bayesian filter
       The  Bayesian  junk mail filter works by examining the words contained in messages.
       You decide yourself what a good and what a bad message is.  Thus the resulting fil-
       ter  is  your  very  personal one; once it is correctly set up, it will filter only
       messages similar to those previously specified by you.

       To use the Bayesian filter, a location for the junk mail database must  be  defined
       first:

           set junkdb=~/.junkdb

       The  junk  mail database does not contain actual words extracted from messages, but
       hashed representations of them.  A foreign person who can read the  database  could
       only examine the frequency of previously known words in your mail.

       If you have sufficient disk space (several 10 MB) available, it is recommended that
       you set the chained-junk-tokens option.  The filter will then  also  consider  two-
       word tokens, improving its accuracy.

       A set of good messages and junk messages must now be available; it is also possible
       to use the incoming new messages for this purpose, although it will of course  take
       some time until the filter becomes useful then.  Do not underestimate the amount of
       statistical data needed; some hundred messages are typically necessary to get  sat-
       isfactory results, and many thousand messages for best operation.  You have to pass
       the good messages to the good command, and the junk messages to the  junk  command.
       If you ever accidentally mark a good message as junk or vice-versa, call the ungood
       or unjunk command to correct this.

       Once a reasonable amount of statistics has been  collected,  new  messages  can  be
       classified  automatically.  The classify command marks all messages that the filter
       considers to be junk, but it does not perform any action on them by default.  It is
       recommended  that  you move these messages into a separate folder just for the case
       that false positives occur, or to pass them to the junk command later again to fur-
       ther  improve the junk mail database.  To automatically move incoming junk messages
       every time the inbox is opened, put lines like the following into your .scores file
       (or whatever name you gave to the file in the last example):

           define junkfilter {
               classify (smaller 20000) :n
               move :j +junk
           }
           set folder-hook-imap://user@host/INBOX=junkfilter

       If you set the verbose option before running the classify command, mailx prints the
       words it uses for calculating the junk status along with their  statistical  proba-
       bilities.   This  can  help you to find out why some messages are not classified as
       you would like them to be.  To see the statistical probability of a given word, use
       the probability command.

       If a junk message was not recognized as such, use the junk command to correct this.
       Also if you encounter a false positive (a good message that was wrongly  classified
       as junk), pass it to the good command.

       Since  the classify command must examine the entire text of all new messages in the
       respective folder, this will also cause all of them to be downloaded from the  IMAP
       server.  You should thus restrict the size of messages for automatic filtering.  If
       server-based filtering is also available, you might  try  if  that  works  for  you
       first.

   Reading HTML mail
       You  need  either  the w3m or lynx utility or another command-line web browser that
       can write plain text to standard output.

           set pipe-text/html="w3m -dump -T text/html"

       or

           set pipe-text/html="lynx -dump -force_html /dev/stdin"

       will then cause HTML message parts to be converted into a more friendly form.

   Viewing PDF attachments
       Most PDF viewers do not accept input directly from a pipe.  It is thus necessary to
       store the attachment in a temporary file, as with

           set pipe-application/pdf="cat >/tmp/mailx$$.pdf; \
                  acroread /tmp/mailx$$.pdf; rm /tmp/mailx$$.pdf"

       Note  that security defects are discovered in PDF viewers from time to time.  Auto-
       matical command execution like this can compromise your system security, in partic-
       ular if you stay not always informed about such issues.

   Signed and encrypted messages with S/MIME
       S/MIME  provides two central mechanisms: message signing and message encryption.  A
       signed message contains some data in addition to the regular text.  The data can be
       used  to  verify  that  the  message  was  sent using a valid certificate, that the
       sender's address in the message header matches that in the  certificate,  and  that
       the message text has not been altered.  Signing a message does not change its regu-
       lar text; it can be read regardless of whether the recipient's software is able  to
       handle  S/MIME.   It  is  thus usually possible to sign all outgoing messages if so
       desired.--Encryption, in contrast, makes the message text invisible for all  people
       except  those  who have access to the secret decryption key.  To encrypt a message,
       the specific recipient's public encryption key must be known.  It is thus not  pos-
       sible  to  send  encrypted  mail to people unless their key has been retrieved from
       either previous communication or public key directories.  A message  should  always
       be  signed  before  it  is  encrypted.   Otherwise,  it  is still possible that the
       encrypted message text is altered.

       A central concept to S/MIME is that of the certification authority (CA).  A CA is a
       trusted  institution  that issues certificates.  For each of these certificates, it
       can be verified that it really originates from the CA, provided that the  CA's  own
       certificate  is  previously  known.   A set of CA certificates is usually delivered
       with OpenSSL and installed on your system.  If you trust the source of your OpenSSL
       software  installation, this offers reasonable security for S/MIME on the Internet.
       In general, a certificate cannot be more secure than the method its CA  certificate
       has  been  retrieved  with, though.  Thus if you download a CA certificate from the
       Internet, you can only trust the messages you verify using that certificate as much
       as you trust the download process.

       The  first thing you need for participating in S/MIME message exchange is your per-
       sonal certificate, including a private key.  The certificate contains public infor-
       mation,  in particular your name and your email address, and the public key that is
       used by others to encrypt messages for you, and to verify signed messages they sup-
       posedly  received from you.  The certificate is included in each signed message you
       send.  The private key must be kept secret.  It is used to  decrypt  messages  that
       were previously encrypted with your public key, and to sign messages.

       For  personal  use, it is recommended that you get a S/MIME certificate from one of
       the major CAs on the Internet using your WWW browser.  (Many CAs  offer  such  cer-
       tificates  for  free.)  You will usually receive a combined certificate and private
       key in PKCS#12 format which mailx does not directly accept  if  S/MIME  support  is
       built using OpenSSL.  To convert it to PEM format, use the following shell command:

           $ openssl pkcs12 -in cert.p12 -out cert.pem -clcerts \
               -nodes

       If  you  omit  the -nodes parameter, you can specifiy an additional PEM pass phrase
       for protecting the private key.  Mailx will then ask you for that pass phrase  each
       time it signs or decrypts a message.  You can then use

           set smime-sign-cert-myname AT myisp.example=cert.pem

       to make this private key and certificate known to mailx.

       If  S/MIME  support  is  built  using NSS, the PKCS#12 file must be installed using
       Mozilla (provided that nss-config-dir is set appropriately, see above), and no fur-
       ther  action  is  necessary  unless  multiple  user certificates for the same email
       address are installed.  In this case, the smime-sign-nickname variable  has  to  be
       set appropriately.

       You can now sign outgoing messages.  Just use

           set smime-sign

       to do so.

       From each signed message you send, the recipient can fetch your certificate and use
       it to send encrypted mail back to you.  Accordingly if somebody sends you a  signed
       message,  you  can do the same.  First use the verify command to check the validity
       of the certificate.  After that, retrieve the certificate and tell  mailx  that  it
       should use it for encryption:

           certsave filename
           set smime-encrypt-user@host=filename

       If S/MIME support is built using NSS, the saved certificate must be installed using
       Mozilla.  The value of the smime-encrypt-user@host is ignored then, but if multiple
       certificates for the recipient are available, the smime-nickname-user@host variable
       must be set.

       You should carefully  consider  if  you  prefer  to  store  encrypted  messages  in
       decrypted  form.   If  you do, anybody who has access to your mail folders can read
       them, but if you do not, you might be unable to read them  yourself  later  if  you
       happen  to  lose your private key.  The decrypt command saves messages in decrypted
       form, while the save, copy, and move commands leave them encrypted.

       Note that neither S/MIME signing nor encryption  applies  to  message  subjects  or
       other header fields.  Thus they may not contain sensitive information for encrypted
       messages, and cannot be trusted even if the  message  content  has  been  verified.
       When  sending  signed  messages,  it  is recommended to repeat any important header
       information in the message text.

   Using CRLs with S/MIME or SSL/TLS
       Certification authorities (CAs) issue certificate revocation lists (CRLs) on a reg-
       ular  basis.  These lists contain the serial numbers of certificates that have been
       declared invalid after they have been issued.  Such  usually  happens  because  the
       private key for the certificate has been compromised, because the owner of the cer-
       tificate has left the organization that is mentioned in the certificate,  etc.   To
       seriously  use  S/MIME  or  SSL/TLS verification, an up-to-date CRL is required for
       each trusted CA.  There is otherwise no method to  distinguish  between  valid  and
       invalidated certificates.  Mailx currently offers no mechanism to fetch CRLs, or to
       access them on the Internet, so you have to retrieve them by some  external  mecha-
       nism.

       If  S/MIME  and  SSL/TLS support are built using OpenSSL, mailx accepts CRLs in PEM
       format only; CRLs in DER format must be converted, e.g. with the shell command

           $ openssl crl -inform DER -in crl.der -out crl.pem

       To tell mailx about the CRLs, a directory that contains all CRL files (and no other
       files)  must be created.  The smime-crl-dir or ssl-crl-dir variables, respectively,
       must then be set to point to that directory.  After that, mailx requires a  CRL  to
       be present for each CA that is used to verify a certificate.

       If  S/MIME and SSL/TLS support are built using NSS, CRLs can be imported in Mozilla
       applications (provided that nss-config-dir is set appropriately).

   Sending mail from scripts
       If you want to send mail from scripts, you must  be  aware  that  mailx  reads  the
       user's  configuration files by default.  So unless your script is only intended for
       your own personal use (as e.g. a cron job), you need to circumvent this by invoking
       mailx like

           MAILRC=/dev/null mailx -n

       You  then  need  to  create a configuration for mailx for your script.  This can be
       done by either pointing the MAILRC variable to a custom configuration file,  or  by
       passing  the  configuration in environment variables.  Since many of the configura-
       tion options are not valid shell variables, the env command is useful in this situ-
       ation.  An invocation could thus look like

           env MAILRC=/dev/null from=scriptreply@domain smtp=host \
                 smtp-auth-user=login smtp-auth-password=secret \
                 smtp-auth=login mailx -n -s "subject" \
                 -a attachment_file recipient@domain <content_file

SEE ALSO
       fmt(1), newaliases(1), openssl(1), pg(1), more(1), vacation(1), ssl(3), aliases(5),
       locale(7), mailaddr(7), sendmail(8)

NOTES
       Variables in the environment passed to mailx cannot be unset.

       The character set conversion relies on the iconv(3)  function.   Its  functionality
       differs  widely between the various system environments mailx runs on.  If the mes-
       sage `Cannot convert from a to b' appears, either some characters within  the  mes-
       sage header or text are not appropriate for the currently selected terminal charac-
       ter set, or the needed conversion is not supported by the  system.   In  the  first
       case,  it  is  necessary  to set an appropriate LC_CTYPE locale (e.g. en_US) or the
       ttycharset variable.  In the second case, the sendcharsets and ttycharset variables
       must  be  set to the same value to inhibit character set conversion.  If iconv() is
       not available at all, the value assigned to sendcharsets must match  the  character
       set that is used on the terminal.

       Mailx expects input text to be in Unix format, with lines separated by newline (^J,
       \n) characters only.  Non-Unix text files that use carriage return (^M, \r) charac-
       ters  in addition will be treated as binary data; to send such files as text, strip
       these characters e. g. by

              tr -d '\015' <input | mailx . . .

       or fix the tools that generate them.

       Limitations with IMAP mailboxes are: It is not possible to edit messages, but it is
       possible  to  append them.  Thus to edit a message, create a local copy of it, edit
       it, append it, and delete the original.  The line count for the header  display  is
       only  appropriate  if  the entire message has been downloaded from the server.  The
       marking of messages as `new' is performed by the IMAP server; use of the exit  com-
       mand  instead  of  quit  will  not cause it to be reset, and if the autoinc/newmail
       variables are unset, messages that arrived during a session will not  be  in  state
       `new'  anymore when the folder is opened again.  Also if commands queued in discon-
       nected mode are committed, the IMAP server will delete the `new' flag for all  mes-
       sages  in  the  changed  folder,  and new messages will appear as unread when it is
       selected for viewing later.  The `flagged', `answered', and `draft' attributes  are
       usually  permanent,  but some IMAP servers are known to drop them without notifica-
       tion.  Message numbers may change with IMAP every time before the prompt is printed
       if  mailx  is  notified by the server that messages have been deleted by some other
       client or process.  In this case, `Expunged n messages'  is  printed,  and  message
       numbers may have changed.

       Limitations  with POP3 mailboxes are: It is not possible to edit messages, they can
       only be copied and deleted.  The line count for the header display is  only  appro-
       priate if the entire message has been downloaded from the server.  The status field
       of a message is maintained by the server between connections; some servers  do  not
       update  it  at  all, and with a server that does, the `exit' command will not cause
       the message status to be reset.  The `newmail' command and the  `newmail'  variable
       have no effect.  It is not possible to rename or to remove POP3 mailboxes.

       If  a  RUBOUT  (interrupt) is typed while an IMAP or POP3 operation is in progress,
       mailx will wait until the operation can be safely aborted, and will then return  to
       the  command  loop and print the prompt again.  When a second RUBOUT is typed while
       mailx is waiting for the operation to complete, the operation itself will  be  can-
       celed.   In  this  case, data that has not been fetched yet will have to be fetched
       before the next command can be performed.  If the canceled operation was  using  an
       SSL/TLS  encrypted  channel, an error in the SSL transport will very likely result,
       and the connection is no longer usable.

       As mailx is a mail user agent, it provides only basic SMTP services.  If  it  fails
       to  contact its upstream SMTP server, it will not make further attempts to transfer
       the message at a later time, and it does not leave  other  information  about  this
       condition  than an error message on the terminal and a `dead.letter' file.  This is
       usually not a problem if the SMTP server is located in the same  local  network  as
       the  computer  on  which  mailx is run.  However, care should be taken when using a
       remote server of an ISP; it might be better to set up  a  local  SMTP  server  then
       which just acts as a proxy.

       Mailx immediately contacts the SMTP server (or /usr/lib/sendmail) even when operat-
       ing in disconnected mode.  It would not make much sense for mailx to defer outgoing
       mail  since  SMTP  servers usually provide much more elaborated delay handling than
       mailx could perform as a client.  Thus the recommended setup for  sending  mail  in
       disconnected  mode  is to configure a local SMTP server such that it sends outgoing
       mail as soon as an external network connection is available again, i.e.  to  advise
       it to do that from a network startup script.

       The junk mail filter follows the concepts developed by Paul Graham in his articles,
       ``A Plan for Spam'', August 2002, <http://www.paulgraham.com/spam.html>, and ``Bet-
       ter  Bayesian  Filtering'',  January 2003, <http://www.paulgraham.com/better.html>.
       Chained tokens are due to a paper by Jonathan  A.  Zdziarski,  ``Advanced  Language
       Classification       using       Chained       Tokens'',       February       2004,
       <http://www.nuclearelephant.com/papers/chained.html>.

       A mail command appeared in Version 1 AT&T Unix.  Berkeley Mail was written in  1978
       by Kurt Shoens.  This man page is derived from from The Mail Reference Manual orig-
       inally written by Kurt Shoens.  Heirloom Mailx enhancements are maintained and doc-
       umented by Gunnar Ritter.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std
       1003.1, 2003 Edition, Standard  for  Information  Technology  --  Operating  System
       Interface  (POSIX),  The  Open  Group  Base  Specifications  Issue 6, Copyright (C)
       2001-2003 by the Institute of Electrical and Electronics  Engineers,  Inc  and  The
       Open  Group.  In the event of any discrepancy between this version and the original
       IEEE and The Open Group Standard, the original IEEE and The Open Group Standard  is
       the   referee   document.   The   original  Standard  can  be  obtained  online  at
       http://www.opengroup.org/unix/online.html .  Redistribution  of  this  material  is
       permitted so long as this notice remains intact.



Heirloom mailx 12.5                          10/9/10                                     MAILX(1)

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