I don't know a lot about SMTP and how it works, so my definition of this problem may be to vague, but here it goes anyway. I have a client that uses exchange server. They have SMTP turned off. (This is what I am not for certain about, there is some SMTP service property that is turned off which is preventing me from sending email programmatically using system.web.mail) I have tried to use MAPI, but I get the error "Class is not licensed for use". I seen an article by Dr. GUI and it talked about getting around Outlook Security Settings, but I think this problem goes a little further. I also tried using CDO and I got the following message "THE SERVER REJECTED ONE OR MORE RECIPIENT ADDRESSES. THE SERVER RESPONSE WAS: 550 5.7.1 UNABLE TO RELAY FOR RANDY_BELCHER@YAHOO.COM" . Anyway, I am about out of ideas to try. I hope you can make since of what I am trying to ask. If so, I hope yo can help me out. TIA.