The original message was received at Fri, 9 Feb 2007 09:22:46 +0100 from linux.cz [102.178.73.9] ----- The following addresses had permanent fatal errors ----- <redhat-cz na linux.cz> ----- Transcript of session follows ----- ... while talking to mail server 18.209.198.148: 550 5.1.2 <redhat-cz na linux.cz>... Host unknown (Name server: host not found)