WHAT'S NEW
Version 1.3b1:

* Compatible with Mac OS X 10.5 (Leopard).
* Universal Binary for both, PowerPC and Intel microprocessors.

Known Issues

After installing Mail.appetizer 1.3 Beta 1, Mail will be launched in the background. I have to figure out if this is related to Mail.appetizer or to plug-ins in general, i.e. a bug in Mail.

Mail.appetizer does not work when Logitech's Scroll Enhancer (comes with Logitech Control Center) is installed. You can uninstall Scroll Enhancer by removing the folder "/Library/InputManagers/LCC Scroll Enhancer Loader". Log out of OS X afterwards. (Thanks to David Linke)