Email Validator   
http://www.bytefoundry.com

Email Validator checks deliverability of email addresses. It does so by first performing a DNS query on the domain name of each email address in order to determine the address of the mail server servicing that domain. Once the mail server is found, a connection is made in the same way as your ISP's mail server would make a connection. Email validator will first attempt to use the SMTP VRFY command to determine deliverability. If the VRFY command is enabled, the mail server will report whether the email address being tested is in fact deliverable, Email Validator will then close the connection and report the result. In many cases the VRFY command is disabled on SMTP servers. If this is the case for any given mail server, Email Validator will then attempt to simulate the delivery of an email message. During this process, the mail server will report whether or not it can accept a message for the email address being tested. Once this is reported, Email Validator will close the connection and report the result. NO EMAIL IS ACTUALLY SENT. Email Validator never gets to that point, so the owner of the email address will not receive any message as a result. Once a list of email addresses has been tested, the user may export all addresses along with test results or simply export all deliverable or non-deliverable addresses in order to clean an existing list or build a new one containing only deliverable addresses. The result for anyone who runs a mailing list, i.e. ezine and newsletter publishers, businesses, political parties, non-profit organizations, etc. can save time and money by sending mail only to deliverable addresses and not have to clean delivery failure notices out of their inboxes.

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.

SpamMonitor   
http://www.digiarch.org

SpamMonitor works in conjunction with file based mail servers, like Mdaemon, MailCoach, MS SMTP service, Winroute, etc. It will monitor for new files with a certain extension and passes all new messages to the spam filter, SpamAssassin. SpamAssassin reads the messages and assigns each message a score based on a comprehensive set of tests. Next SpamMonitor will mark, move or delete each message based on your settings for different scores.

easy2email ASP Email Component   
http://www.easy2email.com

Easy-to-use server side ActiveX email component to effortlessly send email through SMTP mail servers from ASP or ASP.NET web pages. Features quick implementation, SMTP authentication and COM+ integration. A quick test facility is included with the configuration application to test the component without writing a single line of source code. Email messages can be sent in plain text, HTML or other MIME formats. Additional features include multiple attachments, multiple recipients, multiple CC recipients and multiple BCC recipients. Activities can be logged to text file or through ADODB (MS Access, SQL Server etc.). Reference information (for instance an order no, transaction reference etc.) can be logged with each email sent. Flexible licensing options are available.

EmailVerifier   
http://www.email-business.com

Keep your email lists up to date and remove email addresses which do not exist any longer. You just have to define the path of your email lists. As a result you receive a list with guaranteed valid email addresses, a list containg probably valid email addresses and a list with invalid email addresses. The EmailVerifier uses a proper proofing mechanism, because most of the mail servers have disabled the standard checking command. Further it exposes mail servers, which give the OK return value for every email address.