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The popularity of wireless LANs is increasing as is the use of wireless Internet access points, so the need for secure and encrypted e-mail exchanges is becoming more critical. While there are many implementations of e-mail encryption, one of the most popular e-mail servers is Microsoft Exchange 2003 Server which has built-in encryption capabilities.

Microsoft Exchange 2003 Server allows for the exchange of encrypted e-mail with other e-mail servers using Transport Layer Security (TLS) protocol. Without the encryption, user names and passwords can be easily intercepted on a LAN by an employee running a packet sniffing utility or by a hacker sniffing packets coming out of the LAN.

Later in this article, I will demonstrate an example of an intercepted message by the Microsoft Network Monitor without TLS encryption and you will see the full text of the unencrypted message. I will also show an example of how an encrypted message appears in the same packet sniffing utility.

The Exchange server requires an X.509 server certificate for TLS encryption. An X.509 server certificate is a digital form of identification that is typically issued by a certification authority and contains identification information, a validity period, a public key, a serial number and the digital signature of the issuer.

But first some basics.

2. What is Transport Layer Security protocol?

3. How the TLS Protocol Works

4. How to configure TLS encryption on Microsoft Exchange 2003 server

5. Testing and Debugging TLS protocol on Microsoft Exchange 2003 server

6. What do I do if there is no TLS handshake?