[iFonie]

From the code.google page:

Ok, Easy way! Get Mobile Finder from installer.app and we can do this all from the
phone :-)

1. Once installed, run mobile finder.
2. Click the ~ in the top right corner.
3. Double tap Library.
4. Scroll to Mail and double tap.
5. Tap Envelope Index once.
6. Hit the modify button in the middle at the bottom.
7. Tap on it's file name and add something on the end ('old' for example).
8. Click done at the bottom in the middle (where modify was).
9. Hit the home button.
10. Restart iPhone
11. Click the mail icon (you should see that there are no messages for a second).

Done. ;-) Working on 1.1.4

Greets