My /var/log/zimbra.log is really really long, and tail doesn't show much info, but grepping it for "megatron" shows lines similar to this a lot:
/opt/zimbra/log/mailbox.log is equally long, mostly with INFO about MailboxPurges and logins. No mention of megatron in this one though. It's full of our clients email addresses so if you want the full copies of both I can send them in private message to you...
Jul 11 16:57:00 zimbra postfix/lmtp: DC26F30C0EEF: to=<***email@domain****>, relay=none, delay=0.05, delays=0.05/0/0/0, dsn=5.4.4, status=bnced (Host or domain name not found. Name service error for name=megatron.oxygit.local type=A: Host not found)
That seems like our problem! Now, how do I fix this for every account? I haven't really delved into the inner workings of zimbra like this sorry
zimbra@zimbra:/home/oxygen$ zmprov ga ***email@domain*** | grep Transport