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Annoying Spam

Community Veteran
Posts: 1,236
Registered: 02-08-2007

Annoying Spam

I have largely got spam now under control on my own mailserver at home using a combination of blocking lists, Razor2, Spamassison but  about one email a day still slips through.
The spam I receive is all similar but completely different if that makes any sense.
It is all similar because every email is advertising some sort or pornographic link but never the same link.
The subject line is never the same but it always starts with some sort of obscene sentence but the last two or so words always make no sense in the context of the sentence. Here is an example (not an actual example obviously):
"She went to the shop to buy a pint of milk garden shed".
The emails come from all sorts of addresses, hotmail, yahoo, aol etc. but never the same address as I am continuously blacklisting addresses but the email keeps arriving from new addresses.
Spamassisan catches about 90% of it for various reasons, usually Razor2 but about one email a day has absolutely no spam score so will slip through.
I am convinced that this (at least started) as one spam database due to the similarities. Unfortunately, only a human can see the similarities so I am unable to use them to block 100% of it.
Has anyone else experienced this spam? Does anyone know of any further reading on this particular threat?
4 REPLIES
Community Veteran
Posts: 5,472
Thanks: 292
Fixes: 4
Registered: 11-08-2007

Re: Annoying Spam

Have you tried the 'greylisting' technique ?
Community Veteran
Posts: 1,236
Registered: 02-08-2007

Re: Annoying Spam

I had not actually loked at greylisting before. After just a quick look now, it looks very interesting, I will investigate further.
Many thanks for the tip.
Community Veteran
Posts: 1,236
Registered: 02-08-2007

Re: Annoying Spam

I now have greylisting up and running on my Postfix server. Postgrey is very simple to setup. I should know within 24 hours if this has helped with the problem.
Thanks again for this.
Community Veteran
Posts: 1,236
Registered: 02-08-2007

Re: Annoying Spam

That didn't work, several emails still got through today. Looking at the mail log I can see that the emails came from legitimate Yahoo mail servers and did try a second time after being rejected first time.
I think postfix headder checks could maybe be the simple but best option. It won't be difficult to compile a map of keywords to bounce.