sent items disappearing and read, deleted items show as unread

[1dannyd]

The heading pretty much sums it up. One User has items that are disappearing from his sent item box and when I use Exchange tools to track a message it finds nothing. Also, items that he had previously opened and then deleted (and left in his deleted box) are now showing (in the deleted box) as unread.
oooohhhh, spooky. Any ideas?

 

[Zelandakh]

Deleted from Sent Items is usually caused by Auto Archive.

Deleted become unread would be caused, I suspect, by a rule.