From time to time postfix doesn't deliver mails to the lists correct and response with:
PERM_FAILURE: SMTP Error (state 9): 554 <email@example.com>: Relay access denied
or if i will send a mail direct from zimbra with:
mail for <domain.net> loops back to myself
the problem came's that postfix recreate the main.cf file after every restart.. how can i stop that?