CheckFromHeader = [true | false]
The CheckFromHeader slow.conf configuration item can allow the
From: header to be checked for validity.
It also allows the host part of the SMTP MAIL FROM: address
to be check for valitity.
If this CheckFromHeader slow.conf configuration item is declared as
true (or if it is omitted which defaults to true), the Milter
will first check the
From: header (if there is one in the
message). If that header's host part cannot be looked up
with gethostbyname, that bad status is marked by setting
the frm event (as described in the
standard event set).
If this CheckFromHeader slow.conf configuration item is false, the above check is skipped. In the event you have a slow network, or slow DNS lookups, you may wish to define this CheckFromHeader as false, because gethostbyname may cause your Milter to time out and thus to become inefective.