Visit the below Microsoft support lifecycle policy page to view Microsoft’s guidelines for product support from availability to end of product support lifecycle. I had added the support lifecycle policy information for the Exchange Server family of products.
For example, I enclosed Exchange Server 2010 support policy. Do you know that Mainstream support for Exchange 2010 ended at 13th of January 2015? Also it marks that Exchange 2010 entered in its extended support phase.
Hope this helps.