Callum Macdonald » wildcards http://www.callum-macdonald.com Callum on life Wed, 08 Feb 2012 13:52:11 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 Regex spam prevention http://www.callum-macdonald.com/2008/02/02/regex-spam-prevention/ http://www.callum-macdonald.com/2008/02/02/regex-spam-prevention/#comments Sat, 02 Feb 2008 16:28:05 +0000 Callum http://www.callum-macdonald.com/2008/02/02/regex-spam-prevention/ Continue reading →]]> I have been receiving large volumes of spam to random, numerical addresses at my domain. For example 48321819.1928382@, and so on. It’s not practical to block a single address. The spammers make up new addresses at random.

I wanted to block addresses using wildcards. For example, anything that starts with a 4 and ends with @domain.com. I use postfix, so I did some research. I didn’t find much, so I asked on the #postfix FreeNode channel. The very helpful sysmonk introduced me to regex tables in postfix.

So, I have now managed to block a whole bunch of addresses using a few simple regex patterns. The amount of spam I receive has dropped by almost 90% already. Yay! :)

]]> http://www.callum-macdonald.com/2008/02/02/regex-spam-prevention/feed/ 1