This help sheet explains how you deal with deleted messages
When you delete a message it will be placed in the recycle bin. To see what is in your recycle bin click on the Recycle Bin in the vertical menu down the left hand side of the screen.
Any item can be restored to the forum at any time. Just click on the Restore text on the row of the item you want to restore. To remove an item click on the Delete Permanently text on the row of the item you want to delete.