The 2007 versions of Exchange Server and SharePoint Supports Server are set to hit their end-of-life milestones this year. Exchange Server 2007 Service Pack 3 will fall out of "extended support" on April 11, 2017. At that time, it'll be considered to be an "unsupported" product by Microsoft, and security patches won't get delivered, making it a potential security risk to continue to run it. Microsoft offered an advance warning to that effect back in September, although it used its somewhat obsc...

https://rcpmag.com/articles/2017/01/04/support-exchange-sharepoint-2007.aspx