Desperate Spam Countermeasure

The spam hitting one of our mail servers is getting completely out of control. Since this particular server is more of a mailing list broker, exclusively for Japan, rather than try to fight the influx of global spam — which lately even traditional filters and blocklists seem to be ineffective against — we’ve decided to simply not accept email from anywhere except Japan itself.

Andreas Plesner Jacobse maintains an excellent set of geo blocklists, the DNSBL. Turned this on against some of the more naughty spam countries last week. In Postfix for example:

reject_rbl_client cn.countries.nerd.dk

Bye bye China.

Anyway, so far so good. Spam has gone from hundreds (maybe thousands) of messages slipping through our traditional filters each day to a small trickle of Japan-originated spam.

I can’t imagine what it would be like to maintain a large enterprise email farm. Maybe like trying to grow corn on a plantation overrun by an ever surging plague of locusts!

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