Consider the following scenario:
- The Microsoft Lync instant messaging (IM) feature is enabled for Outlook Web App in a Microsoft Exchange Server 2013 environment.
- You create an email message that contains more than seven individual recipients (excluding distribution lists and external recipients). Then, you send the email message.
- A recipient opens the email message in Outlook Web App, and the recipient list in the email message is collapsed. Then, the recipient opens a chat window by clicking the Reply all by IM button.