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 mas-
       ter(8) process manager.

       The local(8) daemon updates queue files and marks  recipi-
       ents  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.

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  excep-
       tions.

SYSTEM-WIDE AND USER-LEVEL ALIASING
       The  system  administrator  can set up one or more system-
       wide sendmail-style alias databases.  Users can have send-
       mail-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  sepa-
       rated  list  of  ~/.forward  like  files  through the for-
       ward_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  recipient.   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 (recipient username), $home (recipient  home  direc-
       tory),  $shell  (recipient  shell),  $recipient  (complete
       recipient address), $extension (recipient  address  exten-
       sion),  $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  charac-
       ters  is  specified with the forward_expansion_filter con-
       figuration parameter.

       An alias or ~/.forward file may list  any  combination  of
       external   commands,  destination  file  names,  :include:
       directives, or mail addresses.  See aliases(5) for a  pre-
       cise  description. Each line in a user's .forward 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 ~/.forward file
       means do not forward mail.

       In order to prevent the mail system from using  up  unrea-
       sonable   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 dupli-
       cate_filter_limit  configuration parameter limits the num-
       ber of remembered recipients.

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

       In order to stop mail forwarding loops early, the software
       adds an optional Delivered-To: header with the final enve-
       lope recipient address. If mail arrives  for  a  recipient
       that is already listed in a Delivered-To: header, the mes-
       sage 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_direc-
       tory  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_com-
       mand configuration parameters. The command  executes  with
       the  privileges  of  the  recipient user (exceptions: sec-
       ondary 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 mail-
       box_transport_maps  and  mailbox_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 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 set-
       ting (alias,  forward)  forbids  command  destinations  in
       :include: files.

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

       The command_execution_directory parameter value is subject
       to  interpolation  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 $recipi-
       ent_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 execu-
       tion_directory_expansion_filter configuration parameter.

       The  command  is  executed directly where possible. Assis-
       tance 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-deliv-
       ery status reports.  A command is forcibly  terminated  if
       it  does  not  complete within command_time_limit seconds.
       Command exit status codes are expected to follow the  con-
       ventions  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  envi-
       ronment  variables. Characters that may have special mean-
       ing to the shell are replaced by underscores.  The list of
       acceptable characters is specified with the command_expan-
       sion_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 following 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 destinations 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  begin-
       ning  with  "From ", and appends an empty line.  The enve-
       lope 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 reg-
       ular 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 enve-
       lope 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  destinations  listed in ~name/.for-
       ward+foo or in ~name/.forward, to the mailbox owned by the
       user name, or it is sent back as undeliverable.

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).  Cor-
       rupted 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 postmaster is notified of bounces and of  other  trou-
       ble.

SECURITY
       The local(8) delivery agent needs a dual personality 1) to
       access the private Postfix queue and IPC mechanisms, 2) to
       impersonate  the recipient and deliver to recipient-speci-
       fied files or commands. It is  therefore  security  sensi-
       tive.

       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  check-
       pointed to file. As a result, the program may occasionally
       deliver more than once to a command or external file. Bet-
       ter 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 Delivered-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 list-
              name-request address localparts: don't  split  such
              addresses  when  the  recipient_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_deliv-
              ered_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 recipient.

       reset_owner_alias (no)
              Reset  the  local(8)  delivery  agent's idea of the
              owner-alias attribute, when delivering  mail  to  a
              child alias that does not have its own owner alias.

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_directory,    fallback_trans-
       port_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  meth-
              ods.

       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)  deliv-
              ery 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 exclu-
              sive 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 duplicate filter  for  aliases(5)  or  vir-
              tual(5) alias expansion, or for showq(8) queue dis-
              plays.

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

       local_destination_recipient_limit (1)
              The maximal number of recipients per message deliv-
              ery 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 com-
              mands.

       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_com-
              mand and $command_execution_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_execu-
              tion_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 recipient.

MISCELLANEOUS CONTROLS
       config_directory (see 'postconf -d' output)
              The  default  location  of  the Postfix main.cf and
              master.cf configuration 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 logging 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 command.

       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 termi-
              nating voluntarily.

       prepend_delivered_header (command, file, forward)
              The message delivery  contexts  where  the  Postfix
              local(8)  delivery  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 exten-
              sion from the lookup key to the lookup result.

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

       recipient_delimiter (empty)
              The set of characters that can separate a user name
              from its address extension (user+foo).

       require_home_directory (no)
              Require that a local(8) recipient's home  directory
              exists before mail delivery is attempted.

       syslog_facility (mail)
              The syslog facility of Postfix logging.

       syslog_name (see 'postconf -d' output)
              The  mail  system  name  that  is  prepended to the
              process name in syslog  records,  so  that  "smtpd"
              becomes, for example, "postfix/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 sys-
       tem 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)