> Recipient: <marvc@xxxxxxxxxxx> > Reason: 5.7.1 Unable to relay for marvc@xxxxxxxxxxx The server thinks that the message is spam (no-relaying). I'm assuming that you've received mail there in the past? If this is a new Exch2k server then you need to configure a Recipient Policy. If this is happening for just one e-mail address then you need to tell the server which IP addresses are permitted to send mail. The server thinks that the message is SPAM mail. Please provide more information about how the server is configured.