Microsoft Exchange

Microsoft Exchange Server is a messaging and collaborative software product developed by Microsoft. It is part of the Microsoft Servers line of server products and is widely used by enterprises using Microsoft infrastructure solutions. Exchange's major features consist of electronic mail, calendaring, contacts and tasks, and support for the mobile and web-based access to information, as well as supporting data storage.

Exchange 2003

Exchange Server 2003 debuted on September 28, 2003. Exchange Server 2003 (currently at Service Pack 2) can be run on Windows 2000 Server (only if Service Pack 4 is first installed) and 32-bit Windows Server 2003, although some new features only work with the latter. Like Windows Server 2003, Exchange Server 2003 has many compatibility modes to allow users to slowly migrate to the new system. This is useful in large companies with distributed Exchange Server environments who cannot afford the downtime and expense that comes with a complete migration.

Exchange 2003 Anti-Spam Filtering: Exchange Server 2003 added several basic filtering methods to Exchange Server. They are not sophisticated enough to eliminate spam, but they can protect against DoS and mailbox flooding attacks. Exchange Server 2000 supported the ability to block a sender's address, or e-mail domain by adding '*@domain.com', which is still supported in Exchange Server 2003. Added filtering methods in Exchange Server 2003 are:

• Connection filtering - messages are blocked from DNS RBL lists[7] or from manually specified IP addresses/ranges
• Recipient filtering - messages blocked when sent to manually specified recipients on the server (for intranet-only addresses) or to any recipients not on the server (stopping spammers from guessing addresses)
• Sender ID filtering - Sender ID, a form of SPF
• Intelligent Message Filter - A free Microsoft add-on that uses heuristic message analysis to block messages or direct them to the "Junk E-Mail" folder in Microsoft Outlook clients.

Exchange 2007

Exchange Server 2007 runs on 64-bit x86-64 versions of Windows Server only, pointing out the substantial performance benefits that 64-bit computing brings to the product.

• Protection: anti-spam, antivirus, compliance, clustering with data replication, improved security and encryption
• Improved Information Worker Access: improved calendaring, unified messaging, improved mobility, improved web access
• Improved IT Experience: 64-bit performance & scalability, command-line shell & simplified GUI, improved deployment, role separation, simplified routing
• Exchange Management Shell: a new command-line shell and scripting language for system administration (based on Windows PowerShell). Shell users can perform every task that can be performed in the Exchange Server graphical user interface plus additional tasks, and can program often-used or complex tasks into scripts that can be saved, shared, and re-used. The Exchange Management Shell has over 375 unique commands to manage features of Microsoft Exchange Server 2007.
• "Unified Messaging" that lets users receive voice mail, e-mail, and faxes in their mailboxes, and lets them access their mailboxes from cell phones and other wireless devices. Voice commands can be given to control and listen to e-mail over the phone (and also send some basic messages, like "I'll be late")
• Removed the database maximum size limit. Database size is now limited by hardware capability and the window for backups and maintenance.
• Increased the maximum number of storage groups and mail databases per server, to 5 each for Standard Edition (from 1 each in Exchange Server 2003 Standard), and to 50 each for Enterprise Edition (from 4 groups and 20 databases in Exchange Server 2003 Enterprise).