Question : Block cyrillic emails in sendmail

Hi,
I have a linux mailserver (CentOS 5.3) with sendmail, I use DNS blacklisting for filtering spam and clamav-milter for viruses. The level of spam is ok with the exception of a few users that receive around 50-100 spam messages/day and all of them in koi8-r encoding (it's cyrillic characters). I need a simple method of blocking or rejecting emails written in cyrillic characters if possible without applying other antispam rules.

Thank you

Answer : Block cyrillic emails in sendmail

Without applying other antispam rules? I don't think so. The only thing I can think of is to use a milter like mimedefang (http://mimedefang.org) and test for the encoding of the body in the filter() section.

This site has an example using the subject instead of the body:
http://lists.roaringpenguin.com/pipermail/mimedefang/2009-April/034698.html

This is not for the faint-of-heart and you really need to know some perl, or be able to figure it out.