In Outlook, on the vendor's own O/S, one can click on the "trash" icon of a message, and then watch in horror as a new message arrives, every message drops down a slot, and then the program recognizes the click on the trash icon of what used to be the message above, which is then deleted. I mean, come on.
It's an old joke that one of the best ways to make someone perpetually unhappy is to teach them proper font kerning.