Assume that you deploy Unified Messaging (UM) in a Microsoft Exchange Server 2013 environment, and integrate the UM IP gateway with a Microsoft Lync Server 2013 environment. When you click a link in a missed call notification email in Microsoft Outlook, you receive the following error message in Lync client:
The specified address is not recognized or does not exist. Please verify the address and try again. If you do not know the correct syntax for this address, contact your support team.
This issue occurs because the Uniform Resource Identifier (URI) parameter is hardcoded by the "tel:" prefix.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.