SYNOPSIS

       nail [-BFintv~] [-s subject] [-a attachment ] [-c cc-addr]
       [-b bcc-addr] [-r from-addr] [-h hops] to-addr ...

       nail [-BeHiInNv~] [-T name] -f [name]

       nail [-BeinNv~] [-u user]


DESCRIPTION

       Nail 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.2 mailx command,
       and offers extensions for MIME messages, POP3 and SMTP.


OPTIONS

       -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.

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

       -f [file]
              Read in the contents of your mbox (or the specified
              file)  for  processing;  when you quit, nail writes
              undeleted messages back to this file.

       -F     Save the message to send in a file named after  the
              local part of the first recipient'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 nail on noisy phone lines.

       -I     Shows the `Newsgroup:' or `Article-Id:'  fields  in
              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.

       -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).

       -R address
              Specify reply-to adress on command line.  Only  the
              first  argument  after  the  -R flag is used as the
              address.

       -T name
              Writes the  `Message-Id'  and  `Article-Id'  header
              fields  of  each  message  read  in  the file name.
              Implies -I.

       -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 dis­
              played on the user's terminal.

       -V     Print nail's version and exit.

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


USAGE

   Sending mail
       To  send  a  message  to  one  or more people, nail can be
       invoked with arguments which are the names  of  people  to
       whom the mail will be sent.  You are then expected to type
       in your message, followed by an 'control-D' at the  begin­
       ning  of  a line.  The section below Replying to or origi­
       nating mail, describes some features of nail available  to
       help you compose your letter.

   Reading mail
       In normal usage nail is given no arguments and checks your
       mail out of the post office, then prints out  a  one  line
       header of each message found.  The current message is ini­
       tially the first message (numbered 1) and can  be  printed
       using  the  print  command  which can be abbreviated 'p').
       Commands such as print and delete can be given a  list  of
       message  numbers as arguments to apply to a number of mes­
       sages at once.  Thus 'delete 1 2' deletes messages  1  and
       2,  while  'delete 1-5' deletes messages 1 through 5.  The
       following special message names exist:

       :n     All new messages.

       :o     All old messages.

       :u     All unread messages.

       :d     All deleted messages.

       :r     All read messages.

       /string
              All messages that contain  string  in  the  subject
              field (case ignored).

       address
              All messages from address.

       .      The current message.

       ;      The  message  that  was previously the current mes­
              sage.

       ,      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  `Refer­
              ences:' field of the current message.

       -      The previous message.

       +      The next message.

       ^      The first message.

       $      The last message.

       *      All messages.

   Replying to or originating mail
       You  can  use  the reply command to set up a response to a
       message, sending it back to the person who  it  was  from.
       Text  you  then type in, up to an end-of-file, defines the
       contents of the message.  While you are composing  a  mes­
       sage,  nail  treats lines beginning 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,
       It  is  also  possible  to  create a personal distribution
       lists  so  that,  for  instance,  you  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 your home directory.   The  current
       list  of such aliases can be displayed with the alias com­
       mand in nail.  System wide distribution lists can be  cre­
       ated  by  editing  /etc/aliases,  see aliases(5) and send­
       mail(8); these are kept in a different  syntax.   In  mail
       you  send,  personal aliases will be expanded in mail sent
       to others so that they will be able to reply to the recip­
       ients.  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.

   Network mail (Internet / ARPA, UUCP, Berknet)
       See mailaddr(7) for a description  of  network  addresses.
       Nail  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, nail 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  con­
       tents,  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 nail.
       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 new­
       lines and horizontal tabulators.

   MIME conformance
       Nail is intended to be a MIME-conformant mail user  agent,
       with the following exception: No special handling of "mul­
       tipart/alternative" messages is performed.  All parts with
       content  types  of "text" or "message" are shown.  This is
       done because the user should see as  much  information  as
       possible.
       verted, resulting in errors when this  process  cannot  be
       done  for  the  entire  text;  if the message contains NUL
       characters, it is not converted.   Attachments  are  never
       converted.  Any message that is displayed on a terminal is
       tried to convert, too, with characters not in the terminal
       character set replaced by question marks.

   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  com­
       mand'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, nail
       types 'applicable messages' and aborts  the  command.   If
       the command begins with a # sign, the line is ignored.

       -      Print  out  the  preceding  message.   If  given  a
              numeric argument n, goes to the n'th previous  mes­
              sage 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.

       alias  (a) With no arguments, prints  out  all  currently-
              defined  aliases.   With  one  argument, 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 you have
              accounts on several machines.  It can  be  used  to
              inform  nail  that  the listed addresses are really
              you.  When you reply to  messages,  nail  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.

       cd     Same as chdir.

       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.

              Same as ignore.

       dp or dt
              Deletes  the  current  message  and prints the next
              message.  If there is no next  message,  nail  says
              'at EOF'.

       echo   Echoes  its  arguments,  resolving special names as
              documented for the folder command.

       edit   (e) Takes a list of messages and  points  the  text
              editor  at  each  one  in turn.  On return from the
              editor, the message is read back in.

       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.

       folders
              List the names of the folders in your folder direc­
              tory.

       folder (fold)  The  folder  command switches to a new mail
              file or folder.  With no arguments,  it  tells  you
              which  file you are currently reading.  If you give
              it an argument, it will write out changes (such  as
              deletions)  you  have  made in the current file and
              read in the new file.  Some special conventions are
              recognized  for  the  name.   #  means the previous
              file, % means  your  system  mailbox,  %user  means
              user's  system mailbox, & means your mbox file, and
              +file  means  a  file  in  your  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.
              A name of the form

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

              is taken as an internet mailbox specification.  The
              supported  protocols  are currently pop3 (POP3) and
              pop3s (i. e. POP3 with SSL/TLS encryption).

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

       Forward
              (For)  Like  forward,  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.

       forward
              (for) Takes a list of messages and a user name  and
              sends each message to the named user.

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

       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 sys­
              tem  mailbox instead of in mbox.  Does not override
              the delete command.

       if     Commands in nail's startup files  can  be  executed
              conditionally  depending on whether you are sending
              or receiving mail with the if command.   For  exam­
              ple, you can do:

                      if receive
                              commands ...
                      endif

              An else form is also available:

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

              Note  that the only allowed conditions are receive,

       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 recip­
              ient'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
              your  home  directory  when  you quit.  This is the
              default action for messages if you do not have  the
              hold option set.

       newmail
              Checks  for  new mail in the current folder without
              commiting any changes before.  If new mail is  pre­
              sent, 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  argument  list,
              types the next matching message.

       New    Same as unread.

       new    Same as unread.

       preserve
              (pre) A synonym for hold.

       Pipe   (Pi)  Like  pipe  but  also  pipes  ignored  header
              fields.

       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.

       Print  (P)  Like  print but also prints out ignored header
              fields.  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.

              recipients of the original message.

       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.

       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 your terminal when you  print  a  mes­
              sage.  All other header fields are suppressed.  The
              Type and Print commands can be used to print a mes­
              sage  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  terminal.
              If  editing  a  system  mailbox,  the  messages are
              marked for deletion.

       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
              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  con­
              tent information.

       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.

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

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

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

       source The source command reads commands from a file.

       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.

       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.

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

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

       Unread Same as unread.


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

       unshortcut
              Deletes the shortcut names given as arguments.

       visual (v)  Takes  a  message list and invokes the display
              editor on each message.

       write  (w) For conventional messages, the body without all
              headers is written.  The output is converted to its
              native format, if necessary.  If a  message  is  in
              MIME multipart format, its first part is written to
              the specified file, and the user  is  asked  for  a
              filename  to save each other part.  In non-interac­
              tive 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 origi­
              nating mail folder.  The contents of  the  destina­
              tion  file  are  overwritten if the file previously
              existed.

       xit    (x) A synonym for exit.

       z      Nail presents  message  headers  in  windowfuls  as
              described under the headers command.  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 without a prefix  specifies  an
              absolute  window number, and a '$' lets nail scroll
              to the last window of messages.

   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.
              attachment list.

       ~A     Inserts  the  string contained in the Sign variable
              (same as `~i Sign').

       ~a     Inserts the string contained in the  sign  variable
              (same as `~i sign').

       ~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 your  home  direc­
              tory into the message.

       ~e     Invoke  the text editor on the message collected so
              far.  After the editing session  is  finished,  you
              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.

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

       ~h     Edit the message header fields by typing  each  one
              in turn and allowing the user to append text to the
              end or modify the field by using the current termi­
              nal erase and kill characters.

       ~istring
              Insert  the  value  of  the  variable  specified by
              string into the message adding a newline  character
              at the end.  If the variable is unset or empty, the
              message remains unaltered.

       ~mmessages
              Read the named  messages  into  the  message  being
              sent,  indented by a tab or by the value of indent­
              prefix.  If no messages  are  specified,  read  the
              current  message.   Message headers currently being
              ignored (by the ignore or retain command)  are  not
              set.

       ~Rstring
              Use string as the Reply-To field.

       ~rfilename
              Read the named file into the message.

       ~sstring
              Cause the named string to become the  current  sub­
              ject 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 you quit the editor, you may resume appending
              text to the end of your message.

       ~wfilename
              Write the message onto the named file.

       ~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 abnor­
              mally, retain the original  text  of  the  message.
              The  command  fmt(1)  is  often  used as command to
              rejustify the message.

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

       ~_nail-command
              Identical to ~:.

       ~~string
              Insert  the  string of text in the message prefaced
              by a single ~.  If  you  have  changed  the  escape
              character,  the you should double that character in
              order to send it.

   Variable options
       Options are controlled via set  and  unset  commands,  see
       their entries for a syntax description.  An option is also
       set if it is passed to nail as part  of  the  environment,
       but  a  value  given  in  a  startup  file overrides this.
       ask or asksub
              Causes  nail  to prompt you for the subject of each
              message you send.  If you  respond  with  simply  a
              newline, no subject field will be sent.

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

       askcc  Causes  you  to  be  prompted for additional carbon
              copy recipients (at the end of each message if bsd­
              compat  is  set).   Responding with a newline indi­
              cates your satisfaction with the current list.

       askbcc Causes you to be prompted for additional blind car­
              bon  copy recipients (at the end of each message if
              bsdcompat is set).  Responding with a newline indi­
              cates your satisfaction with the current list.

       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.

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

       bsdcompat
              Sets some cosmetical features  to  traditional  BSD
              style;  affects  the  default  prompt, the order of
              header fields, the format of  the  header  summary,
              the  output  format  of  the  set  command, and the
              default pager.

       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.

       dot    The  binary  option  dot causes nail to interpret a
              period alone on a line as the terminator of a  mes­
              sage you are sending.

              option is set, nail starts even with an empty mail­
              box.

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

       header Causes the header summary to be written at startup;
              enabled by default.

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

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

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

       keep   This option causes nail  to  truncate  your  system
              mailbox  instead  of  deleting it when it is empty.
              This should always be set, since it prevents  mali­
              cious  users  from  creating fake mail folders in a
              world-writable spool directory.

       keepsave
              When you save a message, nail usually  discards  it
              from  the  originating  folder  when  you quit.  To
              retain all saved messages, set this option.

       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.

       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 to
              be interpreted relative to the directory  given  in
              the  folder  variable  rather  than  to the current
              directory unless it is an absolute pathname.

       page   If set, each message the pipe command prints out is
              file  'dead.letter'  in  your home directory.  This
              option is set by default.

       searchheaders
              If this option is set, then a  message-list  speci­
              fier 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 trans­
              fer agent exits before accepting further  commands.

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

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

       ssl-no-default-ca
              Do  not  load  the  default  CA locations to verify
              SSL/TLS server certificates.

       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 nail.  There are two pitfalls associ­
              ated  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  nail  runs  in
              verbose  mode,  the  actual delivery of messages is
              displayed on the user's terminal.

   String Options
       The string options include the following:

       charset
              The name of the character set  used  by  nail.   If
              unset,  iso-8859-1  is  the default.  The character
              user's home directory.

       EDITOR Pathname of the text editor to use in the edit com­
              mand 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  vari­
              able.   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  fold­
              ers  of  messages.  If this name begins with a '/',
              nail considers it to be an absolute pathname;  oth­
              erwise,  the  folder directory is found relative to
              your home directory.

       from   The address to put into the 'From:'  field  of  the
              message  header.   If  replying  to a message, this
              address is handled as if it were in the  alternates
              list.   If  this variable is set, a 'Sender:' field
              containing  the  user's  name  is  also  generated,
              unless  the variable smtp is set and its value dif­
              fers from localhost.  If the machine's hostname  is
              not  valid at the Internet (for example at a dialup
              machine), you have to set this variable to get cor­
              rect Message-ID header fields.

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

       LISTER Pathname of the directory  lister  to  use  in  the
              folders command.  Default is /bin/ls.

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

              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  nail  com­
              mands that are not understood by other mailx imple­
              mentations.

       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 readable 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  fil­
              tered  through  the  value  of this variable inter­
              preted 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 nail is running on.

       pop3-keepalive
              Many POP3 servers will close the connection after a
              period of inactivity.  Setting 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 vari­
              able is set.

       quote  If  set,  nail  starts  a replying message with the
              original message prefixed by the value of the vari­
              able  indentprefix.  Normally, a heading consisting
              of 'Fromheaderfield wrote:' is printed  before  the
              quotation.   If the string noheading is assigned to
              the quote variable, this heading  is  omitted.   If
              scrolling with the z command.

       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.

       smtp   Normally,  nail invokes sendmail(8) directly
              to transfer messages.  If  smtp  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 standard
              port, a value of server:port can  be  given,
              with port as a name or as a number.

       ssl-ca-dir
              Specifies  a  directory with CA certificates
              for  verification.   See   SSL_CTX_load_ver­
              ify_locations(3) for more information.

       ssl-ca-file
              Specifies  a  file  with CA certificates for
              verification.  See SSL_CTX_load_verify_loca­
              tions(3) for more information.

       ssl-cert
              Sets the file name for a SSL/TLS client cer­
              tificate required by some servers.

       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  speci­
              fied account.

       ssl-cipher-list
              Specifies a list of ciphers for SSL/TLS con­
              nections.  See ciphers(1) for more  informa­
              tion.

       ssl-key
              Sets  the file name for the private key of a
              SSL/TLS client certificate.  If  unset,  the

       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 written to it after it has
              been loaded.

       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  connection  immediately),  `ask'
              (ask whether to continue on standard input),
              `warn'  (print  a  warning  and   continue),
              `ignore'  (do  not perform validation).  The
              default is `ask'.

       record If defined, gives the pathname of  the  file
              used  to  record  all outgoing mail.  If not
              defined, then outgoing mail is not so saved.

       replyto
              The  address  to  put  into  the 'Reply-To:'
              field of the message header.  If replying to
              a  message, this address is handled as if it
              were in the alternates list.

       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  signature  for an individual mes­
              sage.

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

       ttycharset
              The character set of the terminal nail oper­
              ates on.  There is normally no need  to  set
              this  variable since nail can determine this
              automatically by  looking  at  the  LC_CTYPE
              locale  setting; if this succeeds, the value

       HOME   The user's home directory.

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

       MAILRC Is used as startup file instead of ~/.mailrc
              if set.

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

       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

   POP3 client setup
       First, you need the following data from  your  ISP:
       the  host  name  of  its 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 `myname', you can refer to this
       account using the folder command or -f command line
       option with

           pop3://myname@server.myisp.example

       (replace  `pop3://'  with  `pop3s://' if the server
       supports SSL/TLS).  The string is  not  necessarily
       the  same  as  your  internet mail address.  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 con­
       nect:

           shortcut myisp %:pop3://myname@server.myisp.example

       You probably want to put this string into a startup

       You should change the permissions of this  file  to
       0600,  see  chmod(1).  Many POP3 servers will close
       the connection after a short period of  inactivity.
       Use

           set pop3-keepalive=30

       to  send  a  keepalive message each 30 seconds.  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  informa­
       tion)  or  specify  the  protocol version with ssl-
       method.  Contact your ISP if you need a client cer­
       tificate  or if verification of the server certifi­
       cate fails.  If the failed  certificate  is  indeed
       valid, fetch it by executing

           openssl s_client -connect server.myisp.example:pop3s

       (see  s_client(1))  and put it into the file speci­
       fied with ssl-ca-file.

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

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

       will then cause HTML text to be  converted  into  a
       more  friendly  form, the command string depends on
       the browser you are using.


SEE ALSO

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


NOTES

       Variables in the environment passed to nail  cannot
       be unset.

       The  character set conversion relies heavily on the
       iconv(3)  function.   Its   functionality   differs
       widely between the various system environments nail
       runs on.

       POP3 mailboxes are limited in some ways: It is  not
       possible  to edit messages, they can only be copied
       and deleted.  The line count for the header display
       is  only appropriate if the entire message has been
       There is no support for SSL/TLS certificate revoca­
       tion lists (CRLs) yet.

       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 Refer­
       ence Manual originally written by Kurt  Shoens.   A
       revision for nail was done by Gunnar Ritter.



nail 10.3                    11/29/02                     NAIL(1)

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