Google-apps – How to migrate emails from one Google Apps domain to another

One way you might get it to work is by creating a catch-all email account on Google Apps (domain1.com) and have all of its email forward to a single account on domain2.com. Hopefully domain2.com has something similar to SmarterMail's easy solution for creating aliases.

If you are going to use Google Apps to forward your emails, there is a limit of 20 forwarding filters per account. So you should factor that in to decide how many accounts you need.

It seems that Google didn't plan for this kind of feature, at least not as well as SmartMail has.

We needed to setup a distribution list where there were many aliases but they all were delivered to the same users. The best approach we found was creating a fake user account, setting up aliases on that account, forwarding the email to a real group, and using the group membership function to setup the distribution list. Works reasonably well, but having aliases for a group would be better.

Looks like you can also nest groups within groups. There is at least one help topic that recommends this approach. The above mentioned approach does give a few other features however, such as vacation responders and the ability to backup mailing list email using POP/IMAP.