The Postfix configuration file specifies a very small subset of all the parameters that control the operation of the Postfix mail system.Parameters not explicitly specified are left at their default values.
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".
Default values are shown after the parameter name in parentheses, and can be looked up with the "postconf -d" command.
Note: this is not an invitation to make changes to Postfix configuration parameters.
Prior to Postfix 2.6, the response is hard-coded as "450".
Do not change this unless you have a complete understanding of RFC 5321.
This feature is available in Postfix 2.6 and later.
The amount of time between verify(8) address verification database cleanup runs.
An undefined parameter value is replaced with the empty value.
The expressions "$" and "$" are replaced with "value" when "$name" is non-empty.
After each database cleanup run, the verify(8) daemon logs the number of entries that were retained and dropped.