Hey,
Correct me if I'm wrong, but isn't so that OWA should work on both ways when you have e.g. E2007 in old forest and E2013 on new forest?
I have ForestA with E2007 and ForestB with E2013. Some users are migrated from E2007 to E2013 and mail flows and availability services are working just fine. Also when user is moved they profiles are updated automatically.
But now the OWA added some grey hairs to me:
Case1:
when open OWA using the owa.ForestA.com E2007 users are working, E2013 users gets error:
Outlook Web Access could not find a mailbox for ForestB\User01. If the problem continues, contact technical support for your organization and tell them the following: The mailbox may be stored on a Microsoft Exchange 2000 or Microsoft
Exchange 2003 server, or the Active Directory user account was created recently and has not yet replicated to the Active Directory site where this Client Access server is hosted.
Case 2:
When OWA is opened using the owa.ForestB.com E2013 users are working, but E2007 users get an error:
X-OWA-Error: Microsoft.Exchange.Clients.Owa2.Server.Core.OwaUserHasNoMailboxAndNoLicenseAssignedException
E2013 users have Mail User object in ForestA and E2007 users have Mail User object on ForestB. Also both Mail User objects have the ExternalAddress attribute populated.
I have a feeling that this is based on the Autodiscover config, but I have not figure out which part of