I have no idea which server that bounce came from; could you post some details on your setup, letting us know which server is which?
Also, post one of your .forward files.
This sounds like a sendmail problem, which we may not be much help with, but more details will tell us.
When you say "emails seem to reach the zimbra server" what makes you think that?
For the account that generated the bounce, what do you get from
zmprov ga accountname
on the zimbra box? |