You can only get the attached item with the char which posted the item on the exchange. Every other char will only see the standard mail without any items. So try to read your mails with all chars before deleting them.
If this isn't the problem... nope no idea what is wrong.
That's exactly the point.
I always have to log through all my chars and have to check, if there are items in the mails.
But it's a huge amount of mails per char and there are no more than 4 or 5 items returned normally.
But if you don't have this problem, i will wait until i have all items back and will not put them back to exchange for a week. Maybe this solves this problem