Consider the following scenario:
You create a contact card for a user (user A) in Microsoft Outlook.
User A’s email address or telephone number is changed to the email address or telephone number of another user (user B) in the contact card in Outlook.
You perform a search for user A in Microsoft Lync 2010.
You try to start a conversation with user A by sending an instant message.
In this scenario, user B receives the instant message unexpectedly. However, in user B’s conversation window, the sender is user A.
Note This issue may also occur when you try to make a call or send an email message to user A by using Lync 2010. In this situation, user B may receive the email message and see user A as the sender.
To resolve this issue, install the following cumulative update:
2884632 Description of the cumulative update package for Lync 2010: October 2013
To work around this issue, disable Outlook integration in Lync 2010. To do this, follow these steps:
Click the Option icon in Lync 2010, and then open the Lync - Options window.
In the Personal tab, select None in the Personal Information Manager list.
For more information about a similar issue, go to A contact is displayed with an incorrect picture and incorrect presence information in Lync 2010.