Spam Fighting, Revisited

I needed to take several additional steps to make the setup of my domain’s email server and SpamJadoo work well for me. (As an aside: Apparently “jadoo” is a Persian term for magic that is used widely in Indian and Pakistani English. It was new to me.)

My most pressing initial problem with SpamJadoo was that some of my regular correspondents and family members couldn’t get through the grey-listing process. I was finally able to reproduce the problem from a verizon.net account, and sent the “delayed mail” report off to Shiv in Jaipur. He recognized the problem as a rare case of a legitimate mail server that didn’t retry from a “mailbox temporarily unavailable” response within the timing window defined as normal in SpamJadoo. Fortunately, this is a configurable parameter in SpamJadoo, and Shiv widened the timing window to allow for verizon.net’s behavior.

Next, I still had significant amounts of spam getting through my email server and forwarding to GMail. Occasionally, I’d get bursts of them that would get through GMail’s own spam filters and show up in my GMail inbox. They’d be addressed to non-existent mailboxes. They were easy to pick out from their subjects, but I couldn’t understand how they were getting through SpamJadoo, which should have rejected them out of hand.

Either I had forgotten how to view email headers in GMail or they changed it since I did it last, so I pulled up GMail help and searched for the information. The “show original” option is on the drop-down menu to the right of the message title when you are viewing an individual email message, below Reply, Reply to All, and so on. When I looked at the most recent spam of this type, I saw that it had never gone through SpamJadoo at all. The mailbot must have attacked the IP address of my mail server directly instead of looking up the MX record in the domain.

Clearly, the way to stop that was to disable the catchall account. I created an explicit account for forwarding emails to GMail, and created aliases for that account to handle my publicly published addresses. I also switched a few subscriptions from reliable senders that had never generated any spam (including InfoWorld and Second Life) to go directly to GMail. Finally, I deleted the catchall account from my mail server.

Big improvement.

I’m still getting some spam in my GMail account, but there’s a lot less of it, and almost none of it is getting into my inbox: it’s almost all going to the spam folder. Sometimes 10 minutes go by without a spam, which is a big improvement over having multiple spams every minute. Most of what’s getting into my GMail spam folder now was sent directly to GMail.

There is still a small stream of spams to an old mheller.com email address getting through the SpamJadoo grey-listing, virus-checking, and Bayesian filtering, as well as my email server’s virus-checking and Bayesian filtering, but it is being caught by the final spam content filter at GMail. I may go through the validated senders in SpamJadoo and mark the offenders as spammers; I may also discard that old address after taking care of legitimate lists and subscriptions that still use it. Or, I may just leave it alone: it doesn’t do any harm going into my GMail spam folder.