Although past its supported lifecycle, Microsoft Exchange Server 5.5 is still operating in a surprising number of shops. Support for Exchange 5.5 concluded in January 2006.  IT leaders must make a decision to either upgrade or replace their Exchange 5.5 environments before being exposed to unpatched security vulnerabilities.

Past the "Best Before" Date

Exchange Server 5.5 began shipping in early 1998. It became a workhorse in the enterprise messaging arena, and Microsoft issued four Service Packs before the Mainstream Support for Exchange 5.5 ended in December 2005. Responding to the large numbers of customers who needed additional time to complete migration activities, Microsoft announced extended support for Exchange Server 5.5.

Even though extended lifecycle support ended in January 2006, a surprising number of IT shops continue operating Exchange Server 5.5 in production environments. The IT leaders in these shops are exposing the enterprise to security vulnerabilities and unnecessary and avoidable...