This is an SMTP protocol log for virtual server ID 1, connection #19. The client at "194.212.229.227" sent a "rcpt" command, and the SMTP server responded with "550 5.7.1 Unable to relay for vanek at vitkovice-r.cz ". The full command sent was "rcpt TO:<vanek at vitkovice-r.cz>". This will probably cause the connection to fail.

For more information, click http://www.microsoft.com/contentredirect.asp. (application log)