I set up Postfix based on http://www.postfix.org/SOHO_README.html I've got sender_dependent_relay_maps working as expected for the users in the map.
In main.cf, I have relayhost set to null, ie. relayhost= My sender_relay map looks like this: [email protected] [smtp.gmail.com]:587 [email protected] [smtp.gmail.com]:587 sasl_passwd looks like this: [email protected] gmailuser1:gmailpassword1 [email protected] gmailuser2:gmailpassword2 This works just fine for user1 and user2. But let's say [email protected] tries to send mail to [email protected]. user3 is not in the relay map. There's no relayhost= so Postfix sends the mail directly to yahoo.com via smtp. This is documented behavior, from what I can tell. What I want is for Postfix to NOT send the mail for user3 at all. Instead immediately bounce it back to user3 as undeliverable. I'm not quite sure how to do this. I guess I could do something with smtpd_recipient_restrictions, but that looks like I'd need to specify each user that should not send to off site destinations. More things to remember when adding a new user... I'd rather have something that says "If you are not in the sender_dependent_relay_map, I won't send your mail" Thanks
