This feature is available in Postfix 2.6 and later.The amount of time between verify(8) address verification database cleanup runs.Prior to Postfix 2.6, the response is hard-coded as "450".
This form is supported with Postfix versions ≥ 3.0.The remainder of this document is a description of all Postfix configuration parameters.This feature requires that the database supports the "delete" and "sequence" operators.Specify a zero interval to disable database cleanup.When this feature is enabled, the cache may pollute quickly with garbage.
When this feature is disabled, Postfix will generate an address probe for every lookup.
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.
Postfix daemon processes do not use root privileges when opening this file (Postfix 2.5 and later).
The file must therefore be stored under a Postfix-owned directory such as the data_directory.
Default values are shown after the parameter name in parentheses, and can be looked up with the "postconf -d" command.