Assume that a third-party email application such as Lotus Notes is installed on a computer that does not have Microsoft Outlook installed. When you try to send an email message to a contact by clicking the email icon in Microsoft Lync 2010, you receive the following error message:
Cannot connect to Microsoft Office Outlook to send email because Outlook is not responding. Please close any open outlook dialog boxes and try again. If the problem continues, please contact your support team.
The issue occurs because Outlook is the only mail application that Lync 2010 can use to send email messages.
To resolve the issue, install the following cumulative update:
2791382 Description of the cumulative update package for Lync 2010: March 2013