The
verify(8) manual page describes parameters that control
how long information remains cached before it needs to be refreshed,
and how long information can remain "unrefreshed" before it expires.
Postfix uses different controls for positive results (address was
accepted) and for negative results (address was rejected).
Right now, no tools are provided to manage the address verification
database. If the file gets too big, or if it gets corrupted, you
can manually rename or delete the file and run "postfix reload".
The new verify daemon process will then create a new database.
