SpamAssassin charset rule problem in F8

[Luc MAIGNAN]

Hi all,

I'm not sure it's the right place for a such question, but I need experts 
feedback.

I want SpamAssasin to stop all mails that contains a specific charset , in 
my case koi8-r, but my rule doesn't work

header   LR_CHARSET_KR8         Content-Type =~ /charset=(\"|)koi8-r(\"|)/i
describe LR_CHARSET_KR8         ...
score    LR_CHARSET_KR8         100


Has someone an idea ?

BR