Exchange Server, like almost all Microsoft products, has a support lifecycle during which we provide new features, bug fixes, security fixes, and so on. This lifecycle typically lasts for 10 years from the date of the product’s initial release, and the end of this lifecycle is known as the product’s end of support. When Exchange 2010 reaches its end of support on January 14, 2020, Microsoft will no longer provide:

Technical support for problems that may occur
Bug fixes for issues that are discovered and that may impact the stability and usability of the server
Security fixes for vulnerabilities that are discovered and that may make the server vulnerable to security breaches
Time zone updates
Your installation of Exchange 2010 will continue to run after this date. However, due to the changes and risks listed above, we strongly recommend that you migrate from Exchange 2010 as soon as possible. Read more…