Returned mail: Data format error

Úterý Leden 4 00:00:09 CET 2005

The original message was received at Mon, 3 Jan 2005 16:00:09 -0700
from linux.cz [170.138.22.93]

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

----- Transcript of session follows -----
  while talking to linux.cz.:
>>> MAIL From:"Mail Delivery Subsystem" <postmaster na linux.cz>
<<< 501 "Mail Delivery Subsystem" <postmaster na linux.cz>... Refused