Of interest to users of nekodojo.org, but other folks interested in spam control may view also, if you like.

I would very much like to change email programs on neko-base to “Postfix” (current mailer is “sendmail”). This change should be transparent to users, but please test your email and make sure it is coming in and alert me if any problems.

The reason for this change is that I would like to start using some more aggressive anti-spam controls, but sendmail is pretty limited in what it can do. Most everything is possible in sendmail but it’s usually easier in postfix.

Also, postfix will allow some users (and their virtual domains) to have more aggressive spam controls, while some other users may prefer to accept more mail and deal with more spam rather than block any possibly-legitimate mail (though this will be rare).

Background: I am very interested in anti-spam technology, and I would like to update neko-base to the latest “best common practices”. Also, since I would like to work in a spam-blocking area in the future, I would like to try out some new spam-fighting techniques to see if they work well. Ideally I would like to test out new methods by running in “log only” mode for a couple weeks, so mail is delivered but the logs show a warning message when any message would have been caught if the new rule were turned on. Then after a couple weeks it would be turned on for real, if it looked to be safe and effective.

So, before I start any kind of anti-spam changes, please let me know your preference…

Aggressive: If you only receive mail from a few people, usually close friends who have another way to reach you if needed, and you would rather bounce mail from questionable sources, if it means getting less spam, you probably want “aggressive”. Aggressive may bounce some mail from questionable sources, such as people who run their own mail servers on a residential/dynamic cable or dsl, or places where reverse DNS is weird, etc.

Normal: Drop stuff that is “almost certainly spam” but keep stuff that can’t be easily/accurately detected.

Promiscuous: Relay absolutely everything unless blocked by a site-wide policy (like known spamhaus, known open relays). Don’t do any content filtering (though spam score may appear in the headers, all mail will still make it through).