Manual browser: verify(8)
|VERIFY(8)||System Manager's Manual||VERIFY(8)|
NAMEverify - Postfix address verification server
verify [generic Postfix daemon options]
The verify(8) address verification server maintains a record of what recipient addresses are known to be deliverable or undeliverable.
- update address status text
- Update the status and text of the specified address.
- query address
- Look up the status and text for the specified address. If the status is unknown, a probe is sent and an "in progress" status is returned.
The address verification server is not security-sensitive. It does not talk to the network, and it does not talk to local users. The verify server can run chrooted at fixed low privilege.
Problems and transactions are logged to syslogd(8).
Address verification probe messages add additional traffic to the mail queue. Recipient verification may cause an increased load on down-stream servers in the case of a dictionary attack or a flood of backscatter bounces. Sender address verification may cause your site to be blacklisted by some providers.
Changes to main.cf are not picked up automatically, as verify(8) processes are long-lived. Use the command " postfix reload" after a configuration change.
PROBE MESSAGE CONTROLS
- address_verify_sender ($double_bounce_sender)
- The sender address to use in address verification probes; prior to Postfix 2.5 the default was "postmaster".
Available with Postfix 2.9 and later:
- address_verify_sender_ttl (0s)
- The time between changes in the time-dependent portion of address verification probe sender addresses.
- address_verify_map (see 'postconf -d' output)
- Lookup table for persistent address verification status storage.
- address_verify_positive_expire_time (31d)
- The time after which a successful probe expires from the address verification cache.
- address_verify_positive_refresh_time (7d)
- The time after which a successful address verification probe needs to be refreshed.
- address_verify_negative_cache (yes)
- Enable caching of failed address verification probe results.
- address_verify_negative_expire_time (3d)
- The time after which a failed probe expires from the address verification cache.
- address_verify_negative_refresh_time (3h)
- The time after which a failed address verification probe needs to be refreshed.
Available with Postfix 2.7 and later:
- address_verify_cache_cleanup_interval (12h)
- The amount of time between verify(8) address verification database cleanup runs.
PROBE MESSAGE ROUTING CONTROLS
By default, probe messages are delivered via the same route as regular messages. The following parameters can be used to override specific message routing mechanisms.
- address_verify_relayhost ($relayhost)
- Overrides the relayhost parameter setting for address verification probes.
- address_verify_transport_maps ($transport_maps)
- Overrides the transport_maps parameter setting for address verification probes.
- address_verify_local_transport ($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 ($default_transport)
- Overrides the default_transport parameter setting for address verification probes.
Available in Postfix 2.3 and later:
- address_verify_sender_dependent_relayhost_maps ($sender_dependent_relayhost_maps)
- Overrides the sender_dependent_relayhost_maps parameter setting for address verification probes.
Available in Postfix 2.7 and later:
- address_verify_sender_dependent_default_transport_maps ($sender_dependent_default_transport_maps)
- Overrides the sender_dependent_default_transport_maps parameter setting for address verification probes.
- 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.
- ipc_timeout (3600s)
- The time limit for sending or receiving information over an internal communication channel.
- 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 directory.
- 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".
smtpd(8), Postfix SMTP server
cleanup(8), enqueue Postfix message
postconf(5), configuration parameters
syslogd(5), system logging
Use "postconf readme_directory" or " postconf html_directory" to locate this information.
ADDRESS_VERIFICATION_README, address verification howto
The Secure Mailer license must be distributed with this software.
This service was introduced with Postfix version 2.1.
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA