With Lync and Exchange 2010 or 2013, you can configure both platforms so that users can use the Exchange Outlook Web App for Instant Messaging and presence.
The first thing you need to check to make sure that you can do the integration is whether Unified Communications Managed API 4.0 Runtime is installed on your mailbox servers. To verify this, log in to your mailbox servers and look for the following registry key:
This key should point to the folder location of the
Microsoft.Rtc.Internal.Ucweb.dll file. If the key does not exist or does not point to this folder, you ...