Returned mail: see transcript for details

[Post Office]

The original message was received at Sat, 3 Feb 2007 11:45:00 +1000
from 152.190.218.112

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

----- Transcript of the session follows -----
... while talking to linux.cz.:
>>> RCPT To:<sendmail na linux.cz>
<<< 550 5.1.1 <sendmail na linux.cz>... User unknown