One of my customers has an issue where recently (last two weeks) every email that they forward appears in the recipient mailbox greyed out & with a strikethrough. After investigation, it appears that this is because the IMAPDeleted MAPI property is getting set. I'm at a loss to explain what could be causing this behavior. It follows the customers account between computers, doesn't matter if the account is in online or cached mode. Doesn't occur from OWA.
I would assume it is some sort of localized client issue, except that it follows his user account to new computers. I've checked his server rules and our transport rules and don't see anything that sticks out.
Anyone have any ideas?
Thanks, Jason