I have a local EX2013 server and several Outlook 2013 clients. Some of the clients occasionally (once or twice a day) see a random read email turn unread with no apparent reason.
I went through the delivery logs in exchange, and looks like some messages have 2 or more records for delivery (same message, but only one record is readable, other give error when you want to read them). I also looked at the spam filter and I only see one record of the mail going in, not multiple as I saw on delivery reports.
I also went through mail header, but there is nothing special there.
Has anybody noticed this before? What do you think I should be checking?
Here's the delivery report on ECP. Same mail shows there three times. Only one of them is visible, the other 2 gives an error when you want to open it up. The report itself is very simple, nothing to be seen there (I would have to leave out pretty much everything for privacy reasons anyway)