We started with a very simple product: MailFilter — a plug-in for the mail server ArGoSoft Mail Server.
MailFilter had a very limited set of pre-defined conditions and actions, and a typical filter looked like this:
if Subject contains 'viagra'
then delete message
Very soon after, MailFilter had been wrapped into a proxy framework and eWall v1.0 was born in March 2003. It had the same features as MailFilter, but was now able to work in conjunction with any mail server.
Another unique feature of eWall is EWLSP, a Transparency module, that allows the mail server see the actual originating IP address behind eWall, and allows all IP-based features of the mail server to be used. Please click here to read more about the Transparency module.
We started to look at other server-side scripting languages and found very quickly that PHP is suitable for eWall needs: this is time-proven, fast, and lightweight scripting engine, which has plenty of free libraries for almost anything. From DB drivers for major RDBMS engines, such as Oracle, PostgreSQL or MySQL, to lightweight socket libraries — everything can be plugged-in to the PHP engine, and the vast majority of this software is free.
The PHP engine has now been incorporated into eWall v4.0, along with a repository of ready-to-use filters, that are themselves, snippets of PHP code. Although PHP is widely recognized as a programming language for web site development, and the idea to use it for mail filtering may look strange, we recommend you try eWall to see how well it filters SPAM and how flexible and scalable it is. Try it FREE today!