As relaying email by per domain or user is achieved by sender_dependent_relayhost_maps method assigning the domain and individual relay host.
@domain1.com [10.x.10.1]
@domain2.com [20.20.xx.1]
user1@domain3.com [remote-relayhost.com]
I have a few different requirements. As I have configured default external relay remotemta:25 for external delivery of all the domains in my Zimbra. Now I need to bypass email from some users' accounts to directly deliver from my Zimbra server without relaying it to the remote MTA server.
I tried to sender_dependent_relayhost_maps method setting the relay individual relay of the same server. let mail.xyz.com
user1@xyz.com [mail.xyz.com]
I found the loopback to myself information in maillog. So, what needs to be done to bypass some users from relaying mail to default external MTA and send directly from the server itself.
postfix/smtp[19969]: 29CC320CCC8D: to=<xxy@**.com>, relay=none, delay=1188, delays=1188/0.08/0/0, dsn=5.4.6, status=bounced (mail for localhost loops back to myself)