You do realize that you are scanning your outbound mail, and incorrectly brand your ham SPAM-MEDIUM, do you? See the Subject and the headers below.
Also, you're DKIM signing twice, but that's nothing sticking out badly to the recipient, unlike your Subject rewriting. Received: by celer.ajetaci.cz (Postfix, from userid 8) id DAD78A8719; Fri, 1 Apr 2011 12:48:15 +0200 (CEST) X-Spam-Checker-Version: Antispam Ajetaci X-Spam-Level: X-Spam-Report: No, score=-57.0 required=8.0 tests=BAYES_00,MG_WHITELIST, spammedium autolearn=no version=3.2.5 X-Spam-Spam: NO Received: from celer.ajetaci.cz (localhost [127.0.0.1]) by celer.ajetaci.cz (Postfix) with SMTP id 6D32DA8736 for <users@spamassassin.apache.org>; Fri, 1 Apr 2011 12:48:15 +0200 (CEST) -- char *t="\10pse\0r\0dtu\0.@ghno\x4e\xc8\x79\xf4\xab\x51\x8a\x10\xf4\xf4\xc4"; main(){ char h,m=h=*t++,*x=t+2*h,c,i,l=*x,s=0; for (i=0;i<l;i++){ i%8? c<<=1: (c=*++x); c&128 && (s+=h); if (!(h>>=1)||!t[s+h]){ putchar(t[s]);h=m;s=0; }}}