On more than one occassion I was not able to open the messaging application on the HTC / AT&T tilt. It seems that if you are storing your mail on a MicroSD in the expansion slot, that there is a greater likelihood that your mailbox folder will become corrupted. The fix that has worked for me is to use the file explorer navigate to the inbox folder and delete (make a copy of it course before hand)
Steps- Remove the MicroSD card
- Power off the device
- Turn the device back on on
- Insert the Reinsert the MicroSD Card
- Click on the the Messaging application and if all goes well you should be back up and running.
