When your mailbox is located on a Microsoft Exchange Server 2007 server in a Microsoft Exchange Server 2013 and Exchange Server 2007 coexistence environment, you encounter the following issues on the Microsoft Lync client:
You cannot access the conversation history.
You cannot search the address book.
An Exchange Server connection error notification appears the lower-right corner of the Lync client. Specifically, you see the "EWS not deployed" status for EWS Information in Lync Configuration Information.
If Microsoft Outlook is not started, you may receive the following error message from Lync client:
Lync cannot connect to the Exchange server. Please try signing out and signing back in. Outlook contact and calendar information will be unavailable until the connection is restored.
These issues occur because Exchange Server 2007 cannot handle proxy connections that are forwarded to later versions of Exchange Server.
To resolve this issue, install the following update:
2936880 Cumulative Update 5 for Exchange Server 2013
To work around this issue, migrate user mailboxes from Exchange Server 2007 to Exchange Server 2013.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
When this issue occurs, the following AutoDiscover log is generated on the Exchange 2013 server:
ErrorMessage=The SOAP-based AutoDiscover service is not available for mailboxes on Exchange 2007.
For more information about how to upgrade Exchange Server 2007 to Exchange Server 2013, go to the following Microsoft website: