Question : Relay on Exchange Server 2003

I have an Exchange Server 2003 with SMTP connector set to routing to IP Address, everything working fine.
Well I open relay to other server in our company, a unix server (ver 9), this was working with exchange 5.5 and open relay to this server, but now with exchange 2003 not working and I do not see any errors, jus on log I see the following:
2005-03-22 21:23:47 192.1.1.5 -  192.1.1.3 EHLO - 501 0 27 13 0 SMTP - - -
2005-03-22 21:23:47 192.1.1.5 -  192.1.1.3 HELO -  501 0 27 13 0 SMTP - - -
2005-03-22 21:23:47 192.1.1.5 -  192.1.1.3 QUIT - - 240 0 77 4 0 SMTP - - -
Is important you know:  The relay is working with other server windows 2003 without problem, is with unix server that I have problem.
I really thankfull if you can help me.
Thanks

Answer : Relay on Exchange Server 2003

Is the unix box connecting to the 2k3 box or is the 2k3 box connecting to the unix box?  I know that exchange 2003 has enhanced security and mail relaying is disabled by default.  You would need to put the IP or net of the unix box into the smtp connectors allow relay from area.