Developer website: Bay Creations
Google Hosted Mail Notifier will do pretty much the same as the official Google software does for mail checking - except that it will work for your hosted domain.
Note: Google Hosted Mail Notifier is in no way affiliated with the fine people at Google Inc.
What's New
Version 3:
- Bugfixes
Requirements
- Mac OS X 10.4 or later
- Google Apps Email account (free)