I've been getting a lot of user requests for distributed mail capabilities (i.e. mail, users and all, lives entirely on another server from the rest of the services). So it seems like a good time to start thinking about how we can solve that problem for folks in an automated and painless way. There's a FAQ about the current possibilities for achieving some of a solution with current Virtualmin and Webmin features here:
Seems like a full solution can integrate Webmin's synchronize users function, plus a few extra RPC calls to manage the virtual domain maps file, the spam/AV configuration, and making the DNS setup stuff smart enough to know about an alternate mail server address for the MX/mail. records.