I would like to test a zimbra server using the same domain as my current production email system and maybe eventually migrate all my users to it over time. I have an "Idea" but I don't know for sure if it will work or if there is a better way.
The mx for my domain(We will call it example.domain.com) points to the host of our anti-spam/virus gateway appliance. It sends mail to our actual internal SMTP/IMAP/POP production server.
I will setup the zimbra server to have the same example.domain.com and second domain example2.domain.com for the old system to forward too. I would setup an mx record to point example2.domain.com to the new zimbra server. Accounts on the zimbra server will be setup under example.domain.com with an alias to example2.domain.com. When I want email from firstname.lastname@example.org to be delivered to the new zimbra server I would put a forward on the old email system for email@example.com to point to firstname.lastname@example.org. Assuming this will work am I correct that the to field will retain the email@example.com address? Another What about email sent from the zimbra server to users that have not been migrated yet. Will the Zimbra server look up the mx and send an email destined for firstname.lastname@example.org to the gateway device or will it reject the mail because it doesn't have a email@example.com on the system? Is there a much better way to do all this?