Anti-Spam SMTP Proxy Server

Note: It is able to run on any operating system which has a multithreaded perl (5.14 and higher) available. 64bit OS and Perl are highly recommended.

Anti-Spam SMTP Proxy Server is an open-source utility that provides you with multiple adaptable methods of tailoring anti-spam filters for your email client. To be more precise, the application can enable you to implement whitelists, perform virus scanning, block attachments, examine the sender base and manage complex databases – DNSWL, SPF, SRS, URIBL, Bayesian, Greylisting – and add many more filters that your company email client requires.

The idea behind the application is to enable you to block spam at the point where it enters your system, namely the SMTP server. By preventing messages at the SMTP server level, the app can help you overcome the negative effects of having mailboxes filled with spam messages. In other words, it can help companies cut down on the costs associated with storage, transmission, backup and deletion of obsolete email messages.

The platform is designed to run on multiple operating systems and works with most email clients employed by corporations, namely Mercury, Courier, Lotus Notes, Sendmail, Postfix, Exchange, Qmail, Imail and other standard SMTP servers. It is important to note that the utility does not support domains that usually receive mail indirectly.

It can be argued that spammers can very well use an address from the whitelist to continue to send unsolicited messages. However, since the local addresses are not included in the list, the only way spammers could get their hands on contact details is by tricking users to email them directly.

As far as security is concerned, Anti-Spam SMTP Proxy Server can pass through most of the host mail transport features and vulnerabilities. This is the reason why administrators should consider using it separately in a chroot jail. You should keep in mind that the app enables the collection of all email messages and, since non-spam email can contain sensitive information, it is advisable to take the necessary steps to protect the data according to the company's policies.