Active Directory PDC is 2012R2
Exchange is 2013 Std. Edition
Both servers on same subnet
1 main site, 2 remote offices connected via VPN, 15 remote users not connected via VPN, most have very high speed internet.
Main site users have no issues, remote offices have issue rarely, have 1 or 2 home users that have the problem intermittently.
Issue: Outlook 2013 prompts for username and password when connected to exchange server over the WAN/Internet. It happens a few times a day for one user, while she is already logged in and using exchange. Sometimes it happens to other users, but never at the main site.
Question: why is outlook asking for user/pass authentication when it was already passed? Is there a connectivity timeout? Certificate issue? Issue with autodiscover? Internet problems?