I've just finished migrating my Exchange 2010 server to Exchange 2013. Everything went smoothly, even the UM stuff transferred pretty nicely. After having the Ex2010 server powered off for a week I turned it on today and uninstalled EX2010. That went smoothly after I moved my public folder replicas (we don't use public folders, but they were used once upon a time). However, now that the EX2010 software is removed from the server, and the server powered down I'm having an issue with some of my users with outlook clients.
Once the user opens Outlook (2013), the status bar says, "Updating this folder. Connected to: Microsoft Exchange". After a few seconds it says, "This folder is up to date." The user then sees all of their messages. A few seconds later, the status bar will read "This folder was last updated at: HH:MM", and shortly thereafter will switch to "Updating this folder" and the latest dozen or so messages will disappear. After a few seconds it'll say "this folder was updated at: HH:MM" except the time will be a half hour ago. A couple more seconds later, the messages will re-appear in the inbox list and the status bar will say "this folder is up to date."
The messages don't seem to go anywhere. If you've got one selected, it's visible in the reading pane the entire time the disappearing-reappearing act is going on. I checked the email account settings and the server name is <uid>.domain.com rather than <servername>.domain.com which strikes me as odd, but it does work and we're not using http (local network clients appear to be the only ones affected). I've checked mobile devices and OWA and neither seems to exhibit this behavior. So I'm suspicious of the servername. I went into control panel and checked the mail settings there and ran a repair and that didn't change anything (the server name or the behavior).
I'm stumped, but it doesn't appear to be destructive, just a now-you-see-it, now-you-don't that becomes really annoying when you're trying to click on an email (because they all move up/down).