TRIVIAL-REWRITE(8) TRIVIAL-REWRITE(8)
NAME
trivial-rewrite - Postfix address rewriting and resolving
daemon
SYNOPSIS
trivial-rewrite [generic Postfix daemon options]
DESCRIPTION
The trivial-rewrite(8) daemon processes three types of
client service requests:
rewrite context address
Rewrite an address to standard form, according to
the address rewriting context:
local Append the domain names specified with $myo-
rigin or $mydomain to incomplete addresses;
do swap_bangpath and allow_percent_hack pro-
cessing as described below, and strip source
routed addresses (@site,@site:user@domain)
to user@domain form.
remote Append the domain name specified with
$remote_header_rewrite_domain to incomplete
addresses. Otherwise the result is identical
to that of the local address rewriting con-
text. This prevents Postfix from appending
the local domain to spam from poorly written
remote clients.
resolve sender address
Resolve the address to a (transport, nexthop,
recipient, flags) quadruple. The meaning of the
results is as follows:
transport
The delivery agent to use. This is the first
field of an entry in the master.cf file.
nexthop
The host to send to and optional delivery
method information.
recipient
The envelope recipient address that is
passed on to nexthop.
flags The address class, whether the address
requires relaying, whether the address has
problems, and whether the request failed.
verify sender address
Resolve the address for address verification pur-
poses.
SERVER PROCESS MANAGEMENT
The trivial-rewrite(8) servers run under control by the
Postfix master server. Each server can handle multiple
simultaneous connections. When all servers are busy while
a client connects, the master creates a new server
process, provided that the trivial-rewrite server process
limit is not exceeded. Each trivial-rewrite server termi-
nates after serving at least $max_use clients of after
$max_idle seconds of idle time.
STANDARDS
None. The command does not interact with the outside
world.
SECURITY
The trivial-rewrite(8) daemon is not security sensitive.
By default, this daemon does not talk to remote or local
users. It can run at a fixed low privilege in a chrooted
environment.
DIAGNOSTICS
Problems and transactions are logged to syslogd(8).
CONFIGURATION PARAMETERS
On busy mail systems a long time may pass before a main.cf
change affecting trivial-rewrite(8) is picked up. Use the
command "postfix reload" to speed up a change.
The text below provides only a parameter summary. See
postconf(5) for more details including examples.
COMPATIBILITY CONTROLS
resolve_dequoted_address (yes)
Resolve a recipient address safely instead of cor-
rectly, by looking inside quotes.
resolve_null_domain (no)
Resolve an address that ends in the "@" null domain
as if the local hostname were specified, instead of
rejecting the address as invalid.
resolve_numeric_domain (no)
Resolve "user@ipaddress" as "user@[ipaddress]",
instead of rejecting the address as invalid.
Available with Postfix version 2.5 and later:
allow_min_user (no)
Allow a sender or recipient address to have `-' as
the first character.
ADDRESS REWRITING CONTROLS
myorigin ($myhostname)
The domain name that locally-posted mail appears to
come from, and that locally posted mail is deliv-
ered to.
allow_percent_hack (yes)
Enable the rewriting of the form "user%domain" to
"user@domain".
append_at_myorigin (yes)
With locally submitted mail, append the string
"@$myorigin" to mail addresses without domain
information.
append_dot_mydomain (yes)
With locally submitted mail, append the string
".$mydomain" to addresses that have no ".domain"
information.
recipient_delimiter (empty)
The separator between user names and address exten-
sions (user+foo).
swap_bangpath (yes)
Enable the rewriting of "site!user" into
"user@site".
Available in Postfix 2.2 and later:
remote_header_rewrite_domain (empty)
Don't rewrite message headers from remote clients
at all when this parameter is empty; otherwise, re-
write message headers and append the specified
domain name to incomplete addresses.
ROUTING CONTROLS
The following is applicable to Postfix version 2.0 and
later. Earlier versions do not have support for: vir-
tual_transport, relay_transport, virtual_alias_domains,
virtual_mailbox_domains or proxy_interfaces.
local_transport (local:$myhostname)
The default mail delivery transport and next-hop
destination for final delivery to domains listed
with mydestination, and for [ipaddress] destina-
tions that match $inet_interfaces or $proxy_inter-
faces.
virtual_transport (virtual)
The default mail delivery transport and next-hop
destination for final delivery to domains listed
with $virtual_mailbox_domains.
relay_transport (relay)
The default mail delivery transport and next-hop
destination for remote delivery to domains listed
with $relay_domains.
default_transport (smtp)
The default mail delivery transport and next-hop
destination for destinations that do not match
$mydestination, $inet_interfaces, $proxy_inter-
faces, $virtual_alias_domains, $virtual_mail-
box_domains, or $relay_domains.
parent_domain_matches_subdomains (see 'postconf -d' out-
put)
What Postfix features match subdomains of
"domain.tld" automatically, instead of requiring an
explicit ".domain.tld" pattern.
relayhost (empty)
The next-hop destination of non-local mail; over-
rides non-local domains in recipient addresses.
transport_maps (empty)
Optional lookup tables with mappings from recipient
address to (message delivery transport, next-hop
destination).
Available in Postfix version 2.3 and later:
sender_dependent_relayhost_maps (empty)
A sender-dependent override for the global relay-
host parameter setting.
Available in Postfix version 2.5 and later:
empty_address_relayhost_maps_lookup_key (<>)
The sender_dependent_relayhost_maps search string
that will be used instead of the null sender
address.
ADDRESS VERIFICATION CONTROLS
Postfix version 2.1 introduces sender and recipient
address verification. This feature is implemented by
sending probe email messages that are not actually deliv-
ered. By default, address verification probes use the
same route as regular mail. To override specific aspects
of message routing for address verification probes, spec-
ify one or more of the following:
address_verify_local_transport ($local_transport)
Overrides the local_transport parameter setting for
address verification probes.
address_verify_virtual_transport ($virtual_transport)
Overrides the virtual_transport parameter setting
for address verification probes.
address_verify_relay_transport ($relay_transport)
Overrides the relay_transport parameter setting for
address verification probes.
address_verify_default_transport ($default_transport)
Overrides the default_transport parameter setting
for address verification probes.
address_verify_relayhost ($relayhost)
Overrides the relayhost parameter setting for
address verification probes.
address_verify_transport_maps ($transport_maps)
Overrides the transport_maps parameter setting for
address verification probes.
Available in Postfix version 2.3 and later:
address_verify_sender_dependent_relayhost_maps
($sender_dependent_relayhost_maps)
Overrides the sender_dependent_relayhost_maps
parameter setting for address verification probes.
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.
empty_address_recipient (MAILER-DAEMON)
The recipient of mail addressed to the null
address.
ipc_timeout (3600s)
The time limit for sending or receiving information
over an internal communication channel.
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.
relocated_maps (empty)
Optional lookup tables with new contact information
for users or domains that no longer exist.
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.
queue_directory (see 'postconf -d' output)
The location of the Postfix top-level queue direc-
tory.
show_user_unknown_table_name (yes)
Display the name of the recipient table in the
"User unknown" responses.
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".
Available in Postfix version 2.0 and later:
helpful_warnings (yes)
Log warnings about problematic configuration set-
tings, and provide helpful suggestions.
SEE ALSO
postconf(5), configuration parameters
transport(5), transport table format
relocated(5), format of the "user has moved" table
master(8), process manager
syslogd(8), system logging
README FILES
ADDRESS_CLASS_README, Postfix address classes howto
ADDRESS_VERIFICATION_README, Postfix address verification
LICENSE
The Secure Mailer license must be distributed with this
software.
AUTHOR(S)
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
TRIVIAL-REWRITE(8)