The original message was received at Sat, 30 Dec 2006 10:33:03 +0000 from [27.148.10.165] ----- The following addresses had permanent fatal errors ----- <redhat-cz na linux.cz> ----- Transcript of the session follows ----- ... while talking to linux.cz.: 550 5.1.2 <redhat-cz na linux.cz>... Host unknown (Name server: host not found)