I am in the process of moving to Ex 2013 from 2010. I have installed Ex 2013 SP1 on a new server 2012 R2. All of my Ex 2010 servers are SP3 RU 5. Ex 2013 is running and I can connect through the EAC and see all other Exchange servers and connectors that were already in existence. Several puzzling things are happening now that the servers are in coexistence:
1) As soon as Ex 2013 was installed on the network, many Outlook users are continuously being prompted to enter their domain credentials. They can cancel the prompt and Outlook still sends/receives email. No user mailboxes are on Ex 2013 yet. Why is this happening?
2) I am following the Ex 2013 Deployment Assistant and I get to the step to move the Ex 2010 Arbitration mailbox to Ex 2013 and the move does not happen--it just says "syncing" and never completes. I tried moving a test mailbox from Ex 2010 to the 2013 database and I get the same result. I created the move request on the Ex2013 server and I see it as queued on the Ex2010 server, so I know they are "talking" to each other. However, when reviewing the status of the move I see "MapiExceptionNoAccess: Unable to open message store".
3) There seems to be no mail flow on the same Ex2013 server or between the Ex 2010 and 2013 servers. I created two new test user mailboxes in Ex 2013. The Ex2013 mailboxes cannot send/receive to each other or to Ex 2010 users. This seems strange, unless I am completely missing something in the Ex 2013 install?
I know this is a lot in one post, but following the Deployment assistant, I was hoping this would be something that others have faced. Thanks for any input here.