Exchange Server 2003 is the version of Microsoft Exchange released in September 28, 2003 (alongside Server 2003). It replaced Exchange Server 2000 and was replaced by Exchange Server 2007. Exchange Server is the email server product developed by Microsoft, and (most notably), integrates calendaring and contact management software with its email functionality.
Notable new features in Exchange 2003 include:
- Connection filtering (blocking messages from DNS RBL lists or manually specified IP addresses/ranges)
- Recipient filtering (used to stop spammers from guessing addresses by filtering bounce messages)
- Sender ID filtering (a form of Sender Policy Framework (SPF))
- Intelligent Message Filter (heuristic analysis of messages that can be sent to a user's Junk Mail folder)
- Compatibility modes (to ease migration from older versions and reduce/eliminate downtime in a migration)
Mainstream support for Exchange Server 2003 ended April 14, 2009.