Returned mail: Data format error

Úterý Listopad 28 21:46:59 CET 2006

The original message was received at Tue, 28 Nov 2006 22:46:59 +0200
from linux.cz [28.230.221.24]

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

----- Transcript of the session follows -----
... while talking to host 87.84.208.57:
554 Service unavailable; [109.7.236.5] blocked using relays.osirusoft.com, reason: Blocked
Session aborted, reason: lost connection