RelayTest   
http://www.digiarch.org

Relay Test Pro is a tool for network administrators, that allows to test a specified mail server for open relays. It runs series of tests designed to detect open relays and create a detailed report of the findings. The test data can be automatically updated from the web to catch-up with the latest tricks used by spammers. Relay Test Pro is not designed to find vulnerable mail servers - it only scans one server at a time. Key features: Automatic web updates for the test data. Auto and manual test mode. Reference numbering for each test. Real time communication report. Result report with comments.

mxORB   
http://www.mxorb.com

mxORB is a server-side spam filter that consistently blocks over 98% of unsolicited commercial email (also known as spam) at a fraction of the cost of other filtering solutions. mxORB is packed with all of the features you will need to eliminate spam. The amazing low price coupled with a success rate of over 98% gives it an unassailable position in today's marketplace. mxORB can be deployed in two different ways, either directly on your Exchange Server system, or on a separate IIS SMTP mail relay system. mxORB makes use of a number of techniques to filter spam, including: use of real-time Internet databases of known spam senders; filtering that blocks messages based on their content; and attachment filters that can reduce the risk of security incidents such as virus infection. All filtering is performed on the server-side allowing you to protect your email system without the need to configure individual client workstations.

Super Webscan   
http://www.npust.com

It can search for smtp server also locates and identifies open relay SMTP servers. It is an all in one program, you tell it how to scan and it does ALL of the work for you. No more using 3 or 4 programs and wasting hours of your time doing Whois lookups, etc., we do everything.

ORF Enterprise Edition   
http://www.vamsoft.com

ORF Enterprise Edition is an enterprise-level anti-spam solution that helps you to block spam before it reaches your network. It wedges into the SMTP conversations and monitors all incoming SMTP traffic. For the most effective filtering, ORF uses a combination of anti-spam technologies, such as DNSBL's, SURBL's or Greylisting to identify and blacklist unsolicitied emails. Custom tests are provided in addition to the above, e.g. regular expression-supported keyword filtering, attachment filtering or Active Directory-based recipient validation. Using the self-learning Automatic Sender Whitelist of ORF, you can eliminate false positives effectively. You can also create your own IP address, sender and recipient email address lists. While the whitelists can be used to exclude hosts, senders or local mailboxes from filtering, the same type of blacklists help you to reject messages from specific hosts or IP ranges, senders (domains) or local mailboxes. ORF can be used with Windows 2000/2003 built-in IIS SMTP Service and Microsoft Exchange 2000/2003 Servers (which use this service for SMTP communication). ORF was designed with high-performance and robustness in mind, it performs well even under heavy usage. It is being used in networks with a daily average of 2-3 millions incoming email without any performance problems.