I am trying to lock down postfix so the zimbra server doesn't behave as an open relay.
I tried modifying main.cf with the;
smtpd_sender_restrictions = check_sender_access hash:/opt/zimbra/nice_guys
and adding to;
smtpd_client_restrictions = reject_unauth_pipelining, check_client_access hash:/opt/zimbra/nice_guys
But as soon as I save and issue a postfix reload, the main.cf appears to get overwritten.
What have I missed pls?