I have a mail server on debian iredmail/dovecot/postfix everything works good except one domaine that's not receiving my emails because we are blacklisted somewhere and i can't find anyway to fix this.
so the solution i see is to handle emails we are sending to that domain using another smtp server (as relay).
Ihave the appropriate server for this but i don't know how to do it yet. i checked google and fould some articles but all explain how to use a relay to send all emails not for a specific domaine only.
In brief: i want all emails sent to (thisomain.com) served and sent by my relay server (smtp.mysecondmailserver.com).
Any idea how to do this?