I'm sure there must be an obvious answer to my question, but I just can't figure it out.
We would like to host email on Zimbra for members of our non-profit organization. However, for staff, we want to continue to use our in-house Exchange server. How do I tell Zimbra that if it doesn't find a matching user for a specific domain it's hosting mail for that it should relay the messages to another server?
Many thanks for any help you can provide!