Phil’s Diary - [Blog @ http://www.philsdiary.net/]
So over the years I’ve been tweaking my spam filtering, updating spam assassin, adding blacklists in sendmail. And over the years its coped pretty well. Of late though I’ve noticed spam levels going up.
So given a few minutes I’ve had a quick look through some of the spam and realised what’s going on.
Way back when I started, I added some backup MX records to send my mail on somewhere else if my home mailserver died (after all it is just an old PC on a DSL line).
For years this hasn’t caused me any problems. But looking at things now it seems that the spammers are using the backup MX records rather than the main ones. This bypasses most of my inital spam protection (running at the mailserver) and instead leaves it all to spamassassin. That does a great job, but still leaves me with a mailbox full of spam to sift through. Yes I could send to /dev/null, but would rather check things out.
So now I’ve tweaked the backup MX records so the email is rejected and SPAM levels for now are down again.
So now spammers are also rendering backup MX records a liability rather than a benefit. Shame that.
Posted by Phil on August 14, 2007 06:47 PM | Categories: Technology
| TrackBack