Spam Free Email

For anyone who does not know, in SMTP the HELO and EHLO commands are how an SMTP server responds to a greeting from another SMTP server.

Over the past few days I have been monitoring my new SMTP server that I am building, Watching the commands as the come through and some RBL stuff as well. I’ve build some SPF tools and integrated the IP-to-Country data for the most part as well.

One of the things that I have been noticing have been the randomness of the HELO commands. The same IP address will give different HELO commands every time it connects. Not only that but the HELO command does not match up with any of the email addresses.

While this is not a sure sign of spam it surely is a red flag and something that I will be tracking into the future.

I’ve been spending my past few weeks learning Erlang in order to develop the software for my anti-spam project.

I’ve finally made a few breakthroughs that are making the project a bit easier. First off the switch from thinking in a procedural language (Like C) to a functional language is easier said then done. It’s been a bit of a brain tweak to start thinking in different terms.

I also think I’ve gotten the idea of a finite state machine worked into my head as well.

and after reading the RFCs for SMTP I’m rethinking the idea of learning Latin or going to law school ….

In any case, the good news is that I am moving forward again and I’m hoping to have a working SMTP server written in Erlang within a week or two