Currently our organization has an Exchange Server 2007 environment, so i decided that we are going to do a migration to exchange 2013. Everything has went as directed with the co-existed environment up until a user that has been migrated from 2007 to 2013 tries to login to OWA. When the user logs into OWA they are greeted with the message of "Use the following link to open this mailbox with optimal performance the link points to the 2013 server OWA and puts the user into an endless loop of this. Now any new user that is created can login without issues through the 2013 OWA. Now to the weird part.... if i call the server up by IP instead of URL it works without issue.

The admin panel works without issue using the same user.

• Edited by MRNICK0483 13 hours 15 minutes ago

If the user tries accessing OWA from somewhere else, is the result the same?  Try to isolate the issue to the client or the Exchange server.

try to access 2013 mailboxes using 2013 CAS URL. If you access 2013 mailboxes using the URL which is pointing to 2007 CAS URL, then the redirection feature will give you the 2013 CAS URL. since its getting into an endless loop, please check the OWA virtual directory in 2013 CAS servers and check for any http redirection configured there.

The even weirder part is the account works outside of the network. If I try to login with the account internally I get the redirection loop. But if I take a freshly created user and login on the same computer it works great. Could it be something with the internal URL on the virtual directories? I have the internal and external URL set to the same thing on the OWA VD. I can resolve the server name through nslookup internally.
this is using the 13 CAS server.
No redirects configured under IIS

• Edited by MRNICK0483 11 hours 22 minutes ago

What about the same user on a different PC internally?  To answer your question, if the internal URL were misconfigured, it would affect all users, not just one.  That's confirmed by you stating that an entirely different user accessed OWA on the same PC with no issues.