While Teams may be the focal point of Microsoft current collaboration strategy these days, Yammer — the enterprise social network it acquired in 2012 for $1.2 billion — hasn''t been exactly left for dead.In fact, Microsoft unveiled a complete redesign of the enterprise social network at last year Ignite conference, offering up a new user interface based on Microsoft Fluent Design system, smart news feed recommendations, and tighter integration with Outlook, SharePoint and, of course, Teams.