Restoring Mail
It just goes to a white screen and then back to my homescreen
I had the exactly same problem with Mail crashing after you upgrade to 2.0. You do not have to restore back to the factory settings assuming you have a backup on your hard drive.
1) Restore your iPhone to the latest 2.0 firmware. Use either the local copy on your hard drive or press Option key (Mac) or Shift key (Windows).
2) Let the iPhone do a clean install of the firmware.
3) When you are prompted to restore your BACKUP (not firmware), disconnect your iPhone from the computer
4) Go into Settings -> Mail and create any email account (Yahoo, GMail, etc.) and verify the connection.
5) Open the mail application to ensure it is loading properly.
6) Connect the iPhone back to your computer
7) Select the backup that has the data you wish to restore.
Upon restore of the backup, your mail application will be working again.
