I replied to an e-mail thread and spent about a half hour composing a response. Then I chose to highlight and delete the previous conversation. It wasn't just the highlighted portion that got deleted. My entire message that I had worked so hard and long on was deleted also. I immediately tried the "undo" command with no luck. Then I went to my "Drafts" folder hoping there was a backup copy. No luck there either. Why did the entire message get deleted when I only highlighted a portion of it?