Its very easy to recover deleted mails use following steps
Need to be full features install Office 2007
Then type regedit
1> HkEY_lOCAL_MACHINE, SOFTWARE , MICROSOFT,EXCHANGE,OPTAIN,CLIENT
IN RIGHT PANE CREATE DOWN WORD VALUE AND MODIFY AND
TYPE DUMPSTER ALWAYS ON AND VALUE IS 1
THEN GO TO THE TOO AND RECOVER DELETED ITEMS
Schmitdw said he could not delete them once they were in the deleted items folder. In other words he goes to deleted items and he still sees them there, therefore the recover deleted items info here will not help him. They have not been permanently deleted out of the deleted items folder yet.
This sounds like a corrupted profile or pst file issue. Scanpst is a tool that may help with this problem. Next time if you would like to improve an answer please leave the original answer and add your thoughts to the bottom.
The registry key is typed incorrectly. You meant HkEY_LOCAL_MACHINE, SOFTWARE, MICROSOFT, EXCHANGE, CLIENT, OPTIONS.
Or go to the Microsoft website for the solution.