I have installed zimbra successfully on a test bed and have been tweaking it for a month now. I want to go to the next step of deploying the server to production making it our primary email server while our current email server will still be functional until all users are migrated to the zimbra server.

My current server is test.mail.com with its own public ip and domain is mail.com. I want to install the zimbra server and name it zimbra.mail.com with its own public ip, but still wants users being migrated to zimbra to have the same user@test.mail.com email address instead of user@zimbra.mail.com, and receive emails on my zimbra.mail.com server. Can this be done without affecting the functionality of my current email server?

If so, what will be the necessary steps or suggestions to have this working?