    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.

    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  configuration  parame-
           ter.  The  command  executes  with  the  privileges of the
           recipient  user  (exceptions:  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 mail-
           box_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 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).

           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.

           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).  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.

    DELIVERY METHOD CONTROLS
           The precedence of local(8) delivery methods from  high  to
           low  is: aliases, .forward files, mailbox_transport, mail-
           box_command_maps,      mailbox_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  meth-
                  ods.

           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 (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.

           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.

           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.

    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.

           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 the next service request
                  before exiting.

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

           prepend_delivered_header (command, file, forward)
                  The  message  delivery  contexts  where the Postfix
                  local(8) delivery 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 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 separator between user names and address exten-
                  sions (user+foo).

           require_home_directory (no)
                  Whether or not a local(8) recipient's  home  direc-
                  tory  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, "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)