Live updating blacklist of proxy sites
Unnecessary changes are likely to impair the operation of the mail system.
The numerical Postfix SMTP server response code for an access(5) map "defer" action, including "defer_if_permit" or "defer_if_reject".
After each database cleanup run, the verify(8) daemon logs the number of entries that were retained and dropped.
A cleanup run is logged as "partial" when the daemon terminates early after "postfix reload", "postfix stop", or no requests for $max_idle seconds.
The lookup table is persistent by default (Postfix 2.7 and later).
Specify an empty table name to keep the information in volatile memory which is lost after "postfix reload" or "postfix stop".
When this feature is enabled, the cache may pollute quickly with garbage.
The expressions "$" and "$" are replaced with "value" when "$name" is non-empty.
This feature is available in Postfix 2.1 and later.
The time after which a failed probe expires from the address verification cache.
This form is supported with Postfix versions ≥ 3.0.
The remainder of this document is a description of all Postfix configuration parameters.