I'm getting close to deploying my Postfix gateway that will handle mail distribution between our current old IMAP solution and our new Zimbra server.

I have a transport map file that will send users to a specific server based on user name and then I also have a alias file that has user name and username@example.com. I did this because the postfix gateway doesn't have the user accounts locally.

Once again, I know this isn't a postfix group but just want to make sure this configuration makes sense or if there is an easier way to do this instead of maintaining a huge transport file and a huge alias file.

I've been going through various groups and forums and some people talk about virtual maps and domains. I'm not sure if that provides an easier way to do what I'm trying to do.

Any help is greatly appreciated.