|If you have a domain that gets lots of spam, or if you have a domain that you don't use for mail at all that you could get added onto spam lists, here's a nice anti-spammer idea I just had.|
I've noticed that a lot of spam is being sent using software that just goes through every mail exchanger for a domain, so if you have a secondary mail server (as a backup) you get an extra copy of the spam. When configuring the DNS for a domain, you can configure whatever mail exchangers you want. So, if you have a domain for which you no longer wish to receive any email at all, why not configure it with a whole crapload of non-functional mail exchangers?
Any email (which should now be only spam) sent to the domain will go through trying to send to each of the entire list of MX servers. Ideally, those machines won't exist, so it will take 30 seconds or so to determine that each connection is non-responsive. If one were to configure just 20 MX servers for a dead domain, and get 20 email addresses at that domain onto spam lists, that would be over 3 hours worth of spam not getting sent, and at virtually no cost to your bandwidth (just the DNS request). I have now done this to liveandfrivolous.com, configuring it with mail exchangers in the non-routable address ranges to make sure that only the spamming machine and its network are troubled by it. So, if any email address collecting robots want a go, here's some addresses: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20. I realise that some spam-sending programs will do all the addresses at one domain in a single message - even so, they'll be inconvenienced, albeit less so, by the list of duff MXes. Hoorah! [09:39] [7 comments]