Microsoft yesterday announced the release of Office 365 sign-in for Yammer, a feature that will allow users to access Yammer with their Office 365 credentials and to work across Office 365 applications with ease. When a user sign into Yammer, he will be presented with Office 365 login page where he should enter his credentials. Once done, they’ll notice the Office 365 suite navigation bar at the top of their Yammer network. With a single click, these users can quickly toggle between Yammer, Outlook, OneDrive, SharePoint and more to get work done.
Office 365 sign-in for Yammer will follow a phased release schedule between December and March 2015, shipping to Office 365 customers with the following criteria:
Read more about it here.