I have an issue with postfix.
If I set up an autorepsonder (I use a postgresql db, so I insert
email@example.com into alias table; of course this domain is listed into postfix's
transport file) this will work only for local domains.
If I try to send mail from external domains, I receive back
Relay access denied;
As last tentative, if I send in a "conventional way" mail to same address that is "denied" with autorespond operation, I'm able to send it without any problem.