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LOCAL(8)                    System Manager's Manual                   LOCAL(8)



NAME
       local - Postfix local mail delivery

SYNOPSIS
       local [generic Postfix daemon options]

DESCRIPTION
       The  local  daemon  processes  delivery requests from the Postfix queue
       manager to deliver mail to local  recipients.   Each  delivery  request
       specifies  a  queue file, a sender address, a domain or host to deliver
       to, and one or more recipients.  This program expects to  be  run  from
       the master(8) process manager.

       The  local daemon updates queue files and marks recipients as finished,
       or it informs the queue manager that delivery should be tried again  at
       a  later  time.  Delivery  status  reports  are  sent to the bounce(8),
       defer(8) or trace(8) daemon as appropriate.

SYSTEM-WIDE AND USER-LEVEL ALIASING
       The system administrator can set up one or more  system-wide  sendmail-
       style alias databases.  Users can have sendmail-style ~/.forward files.
       Mail for name is delivered  to  the  alias  name,  to  destinations  in
       ~name/.forward,  to  the  mailbox owned by the user name, or it is sent
       back as undeliverable.

       The system administrator can specify a comma/space  separated  list  of
       ~/.forward like files through the forward_path configuration parameter.
       Upon delivery, the local delivery agent tries each pathname in the list
       until a file is found.  The forward_path parameter is subject to inter-
       polation of $user (recipient username), $home  (recipient  home  direc-
       tory),   $shell   (recipient  shell),  $recipient  (complete  recipient
       address), $extension (recipient address extension), $domain  (recipient
       domain),  local  (entire  recipient  address  localpart)  and  $recipi-
       ent_delimiter. The forms ${name?value} and ${name:value} expand  condi-
       tionally  to value when $name is (is not) defined.  Characters that may
       have special meaning to the shell or file system are replaced by under-
       scores.   The  list of acceptable characters is specified with the for-
       ward_expansion_filter configuration parameter.

       An alias or ~/.forward file may list any combination of  external  com-
       mands, destination file names, :include: directives, or mail addresses.
       See aliases(5) for a precise description. Each line in a  user's  .for-
       ward file has the same syntax as the right-hand part of an alias.

       When  an  address is found in its own alias expansion, delivery is made
       to the user instead. When a user is listed in the user's own ~/.forward
       file, delivery is made to the user's mailbox instead.  An empty ~/.for-
       ward file means do not forward mail.

       In order to prevent the mail system from using up unreasonable  amounts
       of  memory,  input records read from :include: or from ~/.forward files
       are broken up into chunks of length line_length_limit.

       While expanding aliases, ~/.forward  files,  and  so  on,  the  program
       attempts to avoid duplicate deliveries. The duplicate_filter_limit con-
       figuration parameter limits the number of remembered recipients.

MAIL FORWARDING
       For the sake of reliability, forwarded mail is re-submitted  as  a  new
       message,  so that each recipient has a separate on-file delivery status
       record.

       In order to stop mail forwarding loops  early,  the  software  adds  an
       optional   Delivered-To:  header  with  the  final  envelope  recipient
       address. If mail arrives for a recipient that is already  listed  in  a
       Delivered-To: header, the message is bounced.

MAILBOX DELIVERY
       The default per-user mailbox is a file in the UNIX mail spool directory
       (/var/mail/user or /var/spool/mail/user); the location can be specified
       with  the  mail_spool_directory configuration parameter. Specify a name
       ending in / for qmail-compatible maildir delivery.

       Alternatively, the per-user mailbox can be a file in  the  user's  home
       directory  with  a  name  specified  via the home_mailbox configuration
       parameter. Specify a relative path name. Specify a name ending in / for
       qmail-compatible maildir delivery.

       Mailbox delivery can be delegated to an external command specified with
       the mailbox_command configuration parameter. The command executes  with
       the privileges of the recipient user (exception: in case of delivery as
       root, the command executes with the privileges of default_privs).

       Mailbox delivery can be delegated  to  alternative  message  transports
       specified  in  the master.cf file.  The mailbox_transport configuration
       parameter specifies a message transport that is  to  be  used  for  all
       local  recipients,  regardless  of  whether  they are found in the UNIX
       passwd database.  The fallback_transport parameter specifies a  message
       transport  for  recipients  that are not found in the UNIX passwd data-
       base.

       In the case of UNIX-style mailbox delivery, the local daemon prepends a
       "From  sender  time_stamp" envelope header to each message, prepends an
       X-Original-To: header with the recipient address as given  to  Postfix,
       prepends  an  optional  Delivered-To:  header  with  the final envelope
       recipient address, prepends a Return-Path:  header  with  the  envelope
       sender address, prepends a >> character to lines beginning with "From ",
       and appends an empty line.  The mailbox is locked for exclusive  access
       while  delivery is in progress. In case of problems, an attempt is made
       to truncate the mailbox to its original length.

       In the case of maildir delivery, the local daemon prepends an  optional
       Delivered-To:   header  with  the  final  envelope  recipient  address,
       prepends an X-Original-To: header with the recipient address  as  given
       to Postfix, and prepends a Return-Path: header with the envelope sender
       address.

EXTERNAL COMMAND DELIVERY
       The allow_mail_to_commands configuration parameter  restricts  delivery
       to external commands. The default setting (alias, forward) forbids com-
       mand destinations in :include: files.

       The command is executed directly  where  possible.  Assistance  by  the
       shell  (/bin/sh on UNIX systems) is used only when the command contains
       shell magic characters, or when the command invokes  a  shell  built-in
       command.

       A limited amount of command output (standard output and standard error)
       is captured for inclusion with non-delivery status reports.  A  command
       is   forcibly   terminated   if   it  does  not  complete  within  com-
       mand_time_limit seconds.  Command exit status  codes  are  expected  to
       follow the conventions defined in <sysexits.h>.

       A  limited  amount of message context is exported via environment vari-
       ables. Characters that may  have  special  meaning  to  the  shell  are
       replaced  by  underscores.  The list of acceptable characters is speci-
       fied with the command_expansion_filter configuration parameter.

       SHELL  The recipient user's login shell.

       HOME   The recipient user's home directory.

       USER   The bare recipient name.

       EXTENSION
              The optional recipient address extension.

       DOMAIN The recipient address domain part.

       LOGNAME
              The bare recipient name.

       LOCAL  The entire recipient address localpart (text to the left of  the
              rightmost @ character).

       RECIPIENT
              The entire recipient address.

       SENDER The entire sender address.

       The  PATH  environment  variable  is always reset to a system-dependent
       default path, and environment variables whose names are blessed by  the
       export_environment configuration parameter are exported unchanged.

       The current working directory is the mail queue directory.

       The local daemon prepends a "From sender time_stamp" envelope header to
       each message, prepends an  X-Original-To:  header  with  the  recipient
       address  as given to Postfix, prepends an optional Delivered-To: header
       with the final recipient  envelope  address,  prepends  a  Return-Path:
       header with the sender envelope address, and appends no empty line.

EXTERNAL FILE DELIVERY
       The  delivery  format  depends on the destination filename syntax.  The
       default is to use UNIX-style mailbox format.  Specify a name ending  in
       / for qmail-compatible maildir delivery.

       The  allow_mail_to_files  configuration parameter restricts delivery to
       external files. The default setting (alias, forward) forbids file  des-
       tinations in :include: files.

       In the case of UNIX-style mailbox delivery, the local daemon prepends a
       "From sender time_stamp" envelope header to each message,  prepends  an
       X-Original-To:  header  with the recipient address as given to Postfix,
       prepends an optional Delivered-To:  header  with  the  final  recipient
       envelope  address, prepends a >&gt; character to lines beginning with "From
       ", and appends an empty line.  The envelope sender address is available
       in the Return-Path: header.  When the destination is a regular file, it
       is locked for exclusive access while delivery is in progress.  In  case
       of problems, an attempt is made to truncate a regular file to its orig-
       inal length.

       In the case of maildir delivery, the local daemon prepends an  optional
       Delivered-To:  header  with  the  final envelope recipient address, and
       prepends an X-Original-To: header with the recipient address  as  given
       to  Postfix.   The  envelope sender address is available in the Return-
       Path: header.

ADDRESS EXTENSION
       The optional recipient_delimiter configuration parameter specifies  how
       to separate address extensions from local recipient names.

       For  example,  with  "recipient_delimiter  =  +",  mail for name+foo is
       delivered to the alias name+foo or to the alias name, to  the  destina-
       tions listed in ~name/.forward+foo or in ~name/.forward, to the mailbox
       owned by the user name, or it is sent back as undeliverable.

       In all cases the  local  daemon  prepends  an  optional  `Delivered-To:
       header line with the final recipient address.

DELIVERY RIGHTS
       Deliveries  to  external  files and external commands are made with the
       rights of the receiving user on whose behalf the delivery is made.   In
       the  absence  of a user context, the local daemon uses the owner rights
       of the :include: file or alias database.  When those files are owned by
       the  superuser,  delivery  is  made  with the rights specified with the
       default_privs configuration parameter.

STANDARDS
       RFC 822 (ARPA Internet Text Messages)

DIAGNOSTICS
       Problems and transactions are logged to syslogd(8).  Corrupted  message
       files are marked so that the queue manager can move them to the corrupt
       queue afterwards.

       Depending on the setting of the notify_classes parameter, the  postmas-
       ter is notified of bounces and of other trouble.

BUGS
       For  security reasons, the message delivery status of external commands
       or of external files is never checkpointed to file. As  a  result,  the
       program  may occasionally deliver more than once to a command or exter-
       nal file. Better safe than sorry.

       Mutually-recursive aliases or ~/.forward files are not detected  early.
       The  resulting  mail forwarding loop is broken by the use of the Deliv-
       ered-To: message header.

CONFIGURATION PARAMETERS
       Changes to main.cf are picked up automatically, as  local(8)  processes
       run for only a limited amount of time. Use the command "postfix reload"
       to speed up a change.

       The text below provides only a parameter summary. See  postconf(5)  for
       more details including examples.

COMPATIBILITY CONTROLS
       biff (yes)
              Whether or not to use the local biff service.

       expand_owner_alias (no)
              When  delivering  to  an  alias  "aliasname" that has an "owner-
              aliasname" companion alias, set the envelope sender  address  to
              the expansion of the "owner-aliasname" alias.

       owner_request_special (yes)
              Give  special  treatment  to owner-listname and listname-request
              address localparts: don't don't split such  addresses  when  the
              recipient_delimiter is set to "-".

       sun_mailtool_compatibility (no)
              Obsolete SUN mailtool compatibility feature.

DELIVERY METHOD CONTROLS
       The  precedence  of  local(8)  delivery  methods  from  high to low is:
       aliases, .forward files, mailbox_transport, mailbox_command_maps, mail-
       box_command, home_mailbox, mail_spool_directory, fallback_transport and
       luser_relay.

       alias_maps (see 'postconf -d' output)
              The alias databases that are used for local(8) delivery.

       forward_path (see 'postconf -d' output)
              The local(8) delivery agent search list for finding  a  .forward
              file with user-specified delivery methods.

       mailbox_transport (empty)
              Optional  message  delivery transport that the local(8) delivery
              agent should use for mailbox delivery to all  local  recipients,
              whether or not they are found in the UNIX passwd database.

       mailbox_command_maps (empty)
              Optional  lookup  tables with per-recipient external commands to
              use for local(8) mailbox delivery.

       mailbox_command (empty)
              Optional external  command  that  the  local(8)  delivery  agent
              should use for mailbox delivery.

       home_mailbox (empty)
              Optional  pathname  of  a  mailbox  file  relative to a local(8)
              user's home directory.

       mail_spool_directory (see 'postconf -d' output)
              The directory where local(8) UNIX-style mailboxes are kept.

       fallback_transport (empty)
              Optional message delivery transport that the  local(8)  delivery
              agent  should use for names that are not found in the aliases(5)
              database or in the UNIX passwd database.

       luser_relay (empty)
              Optional catch-all destination for unknown local(8) recipients.

MAILBOX LOCKING CONTROLS
       deliver_lock_attempts (20)
              The maximal number of attempts to acquire an exclusive lock on a
              mailbox file or bounce(8) logfile.

       deliver_lock_delay (1s)
              The  time  between  attempts  to  acquire an exclusive lock on a
              mailbox file or bounce(8) logfile.

       stale_lock_time (500s)
              The time after which  a  stale  exclusive  mailbox  lockfile  is
              removed.

       mailbox_delivery_lock (see 'postconf -d' output)
              How  to  lock  a  UNIX-style  local(8) mailbox before attempting
              delivery.

RESOURCE AND RATE CONTROLS
       command_time_limit (1000s)
              Time limit for delivery to external commands.

       duplicate_filter_limit (1000)
              The maximal number of addresses remembered by the address dupli-
              cate filter for aliases(5) or virtual(5) alias expansion, or for
              showq(8) queue displays.

       local_destination_concurrency_limit (2)
              The maximal number of parallel deliveries  via  the  local  mail
              delivery  transport  to the same recipient (when "local_destina-
              tion_recipient_limit = 1") or the  maximal  number  of  parallel
              deliveries  to  the  same  local  domain  (when  "local_destina-
              tion_recipient_limit > 1").

       local_destination_recipient_limit (1)
              The maximal number of recipients per message  delivery  via  the
              local mail delivery transport.

       mailbox_size_limit (51200000)
              The  maximal  size of any local(8) individual mailbox or maildir
              file, or zero (no limit).

SECURITY CONTROLS
       allow_mail_to_commands (alias, forward)
              Restrict local(8) mail delivery to external commands.

       allow_mail_to_files (alias, forward)
              Restrict local(8) mail delivery to external files.

       command_expansion_filter (see 'postconf -d' output)
              Restrict the characters that the local(8) delivery agent  allows
              in $name expansions of $mailbox_command.

       default_privs (nobody)
              The  default  rights  used  by  the  local(8) delivery agent for
              delivery to external file or command.

       forward_expansion_filter (see 'postconf -d' output)
              Restrict the characters that the local(8) delivery agent  allows
              in $name expansions of $forward_path.

MISCELLANEOUS CONTROLS
       config_directory (see 'postconf -d' output)
              The  default  location of the Postfix main.cf and master.cf con-
              figuration files.

       daemon_timeout (18000s)
              How much time a Postfix daemon process  may  take  to  handle  a
              request before it is terminated by a built-in watchdog timer.

       export_environment (see 'postconf -d' output)
              The  list  of  environment variables that a Postfix process will
              export to non-Postfix processes.

       ipc_timeout (3600s)
              The time limit for sending  or  receiving  information  over  an
              internal communication channel.

       local_command_shell (empty)
              Optional shell program for local(8) delivery to non-Postfix com-
              mand.

       max_idle (100s)
              The maximum amount of time that an idle Postfix  daemon  process
              waits for the next service request before exiting.

       max_use (100)
              The  maximal number of connection requests before a Postfix dae-
              mon process terminates.

       prepend_delivered_header (command, file, forward)
              The message delivery contexts where the Postfix local(8)  deliv-
              ery agent prepends a Delivered-To:  message header.

       process_id (read-only)
              The process ID of a Postfix command or daemon process.

       process_name (read-only)
              The process name of a Postfix command or daemon process.

       propagate_unmatched_extensions (canonical, virtual)
              What  address  lookup  tables copy an address extension from the
              lookup key to the lookup result.

       queue_directory (see 'postconf -d' output)
              The location of the Postfix top-level queue directory.

       recipient_delimiter (empty)
              The  separator  between  user  names  and   address   extensions
              (user+foo).

       require_home_directory (no)
              Whether  or not a local(8) recipient's home directory must exist
              before mail delivery is attempted.

       syslog_facility (mail)
              The syslog facility of Postfix logging.

       syslog_name (postfix)
              The mail system name that is prepended to the  process  name  in
              syslog  records,  so  that  "smtpd" becomes, for example, "post-
              fix/smtpd".

FILES
       The following are examples; details differ between systems.
       $HOME/.forward, per-user aliasing
       /etc/aliases, sytem-wide alias database
       /var/spool/mail, system mailboxes

SEE ALSO
       qmgr(8), queue manager
       bounce(8), delivery status reports
       newaliases(1), create/update alias database
       postalias(1), create/update alias database
       aliases(5), format of alias database
       postconf(5), configuration parameters
       syslogd(8), system logging

LICENSE
       The Secure Mailer license must be distributed with this software.

HISTORY
       The Delivered-To: message header appears in the qmail system by  Daniel
       Bernstein.

       The maildir structure appears in the qmail system by Daniel Bernstein.

AUTHOR(S)
       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA



                                                                      LOCAL(8)