LOCAL(8)                                                              LOCAL(8)



NAME
       local - Postfix local mail delivery

SYNOPSIS
       local [generic Postfix daemon options]

DESCRIPTION
       The  local(8) 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(8)  daemon  updates queue files and marks recipients as fin-
       ished, 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.

CASE FOLDING
       All delivery decisions are made using the bare recipient name (i.e. the
       address  localpart),  folded  to  lower  case.   See also under ADDRESS
       EXTENSION below for a few exceptions.

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.

       Delivery via ~/.forward files is done with the privileges of the recip-
       ient.  Thus, ~/.forward like files must be readable by  the  recipient,
       and  their  parent directory needs to have "execute" permission for the
       recipient.

       The forward_path parameter is subject to interpolation of $user (recip-
       ient  username),  $home  (recipient  home directory), $shell (recipient
       shell), $recipient (complete recipient address), $extension  (recipient
       address  extension), $domain (recipient domain), $local (entire recipi-
       ent   address   localpart)   and   $recipient_delimiter.   The    forms
       ${name?value}  and  ${name:value}  expand  conditionally  to value when
       $name is (is not) defined.  Characters that may have special meaning to
       the  shell  or  file  system  are replaced by underscores.  The list of
       acceptable characters is specified  with  the  forward_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_maps and mailbox_command configuration parameters.
       The command executes with the privileges of the recipient user  (excep-
       tions:  secondary  groups are not enabled; 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_maps and mail-
       box_transport configuration  parameters  specify  an  optional  message
       transport  that  is  to be used for all local recipients, regardless of
       whether they  are  found  in  the  UNIX  passwd  database.   The  fall-
       back_transport_maps   and   fallback_transport  parameters  specify  an
       optional message transport for recipients that are  not  found  in  the
       aliases(5) or UNIX passwd database.

       In  the  case  of  UNIX-style  mailbox  delivery,  the  local(8) 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 exclu-
       sive 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.

       Optionally, the process working directory is changed to the path speci-
       fied with command_execution_directory (Postfix 2.2 and later).  Failure
       to change directory causes mail to be deferred.

       The  command_execution_directory parameter value is subject to interpo-
       lation of $user (recipient username), $home (recipient home directory),
       $shell  (recipient  shell),  $recipient  (complete  recipient address),
       $extension (recipient address extension), $domain  (recipient  domain),
       $local  (entire  recipient address localpart) and $recipient_delimiter.
       The forms ${name?value} and ${name:value} expand conditionally to value
       when $name is (is not) defined.  Characters that may have special mean-
       ing to the shell or file system are replaced by underscores.  The  list
       of   acceptable  characters  is  specified  with  the  execution_direc-
       tory_expansion_filter configuration parameter.

       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>.  Exit status 0 means
       normal successful completion.

       Postfix version 2.3 and later support RFC  3463-style  enhanced  status
       codes.   If  a  command terminates with a non-zero exit status, and the
       command output begins with an enhanced status code,  this  status  code
       takes precedence over the non-zero exit status.

       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).

       ORIGINAL_RECIPIENT
              The  entire  recipient  address, before any address rewriting or
              aliasing (Postfix 2.5 and later).

       RECIPIENT
              The entire recipient address.

       SENDER The entire sender address.

       Additional remote client information is made available via the  follow-
       ing environment variables:

       CLIENT_ADDRESS
              Remote client network address. Available as of Postfix 2.2.

       CLIENT_HELO
              Remote  client  EHLO  command parameter. Available as of Postfix
              2.2.

       CLIENT_HOSTNAME
              Remote client hostname. Available as of Postfix 2.2.

       CLIENT_PROTOCOL
              Remote client protocol. Available as of Postfix 2.2.

       SASL_METHOD
              SASL authentication method specified in the remote  client  AUTH
              command. Available as of Postfix 2.2.

       SASL_SENDER
              SASL  sender  address  specified  in the remote client MAIL FROM
              command. Available as of Postfix 2.2.

       SASL_USERNAME
              SASL username specified  in  the  remote  client  AUTH  command.
              Available as of Postfix 2.2.

       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(8) 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(8) 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 > 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 original 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(8) 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(8) 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)
       RFC 3463 (Enhanced status codes)

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.

SECURITY
       The  local(8)  delivery agent needs a dual personality 1) to access the
       private Postfix queue and IPC mechanisms, 2) to impersonate the recipi-
       ent  and deliver to recipient-specified files or commands. It is there-
       fore security sensitive.

       The local(8) delivery agent disallows regular  expression  substitution
       of $1 etc. in alias_maps, because that would open a security hole.

       The  local(8)  delivery  agent will silently ignore requests to use the
       proxymap(8) server within alias_maps. Instead it will  open  the  table
       directly.  Before Postfix version 2.2, the local(8) delivery agent will
       terminate with a fatal error.

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 split such addresses when the recipi-
              ent_delimiter is set to "-".

       sun_mailtool_compatibility (no)
              Obsolete SUN mailtool compatibility feature.

       Available in Postfix version 2.3 and later:

       frozen_delivered_to (yes)
              Update the local(8) delivery agent's idea of  the  Delivered-To:
              address  (see  prepend_delivered_header) only once, at the start
              of a delivery attempt; do not update the  Delivered-To:  address
              while expanding aliases or .forward files.

       Available in Postfix version 2.5.3 and later:

       strict_mailbox_ownership (yes)
              Defer  delivery  when a mailbox file is not owned by its recipi-
              ent.

DELIVERY METHOD CONTROLS
       The precedence of local(8)  delivery  methods  from  high  to  low  is:
       aliases,  .forward  files,  mailbox_transport_maps,  mailbox_transport,
       mailbox_command_maps, mailbox_command, home_mailbox,  mail_spool_direc-
       tory, fallback_transport_maps, 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_maps (empty)
              Optional  lookup  tables  with  per-recipient  message  delivery
              transports  to use for local(8) mailbox delivery, whether or not
              the recipients are found in the UNIX passwd database.

       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_maps (empty)
              Optional  lookup  tables  with  per-recipient  message  delivery
              transports for recipients that the local(8) delivery agent could
              not find in the aliases(5) or UNIX password database.

       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)
              or UNIX password database.

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

       Available in Postfix version 2.2 and later:

       command_execution_directory (empty)
              The local(8) delivery agent working directory  for  delivery  to
              external command.

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  and  $command_execu-
              tion_directory.

       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.

       Available in Postfix version 2.2 and later:

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

       Available in Postfix version 2.5.3 and later:

       strict_mailbox_ownership (yes)
              Defer delivery when a mailbox file is not owned by  its  recipi-
              ent.

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.

       delay_logging_resolution_limit (2)
              The  maximal  number of digits after the decimal point when log-
              ging sub-second delay values.

       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 an incoming connection before terminating voluntarily.

       max_use (100)
              The maximal number of incoming connections that a Postfix daemon
              process will service before terminating voluntarily.

       prepend_delivered_header (command, file, forward)
              The message delivery contexts where the Postfix local(8)  deliv-
              ery  agent  prepends  a  Delivered-To:   message header with the
              address that the mail was delivered to.

       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, system-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
       master(5), generic daemon options
       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)
