Returned mail: see transcript for details

[Automatic Email Delivery Software]

The original message was received at Fri, 19 Jan 2007 13:00:13 +0300
from linux.cz [174.230.199.254]

----- The following addresses had permanent fatal errors -----
sendmail na linux.cz

----- Transcript of session follows -----
... while talking to 52.83.35.148:
550 5.1.2 <sendmail na linux.cz>... Host unknown (Name server: host not found)