Hybrid Exchange 2007/2013 and Lync EWS Integration

I came across an interesting issue recently with a client currently running Exchange 2007 and looking to migrate to Exchange Online. Since Update Rollup 10 for Exchange 2007 Service Pack 3, it has become possible to coexist Exchange 2oo7 and Exchange 2013.

After installing Exchange 2013 as the Hybrid server, this particular client ran into an issue with the Lync 2013 client losing EWS integration with any mailboxes that still reside on Exchange 2007. The net effect of this is that any users that hadn’t been migrated from Exchange 2007 to Exchange 2013 or Office 365 would have to rely on Outlook MAPI (and Outlook being open) for anything to do with the Personal Information Manager feature of Lync.… [Keep reading] “Hybrid Exchange 2007/2013 and Lync EWS Integration”