Ok so I made a virtual machine, hosting server 2003 enterprize SP2, I used the "manage my server" itemto make this an Active Directory, Mail and IIS server, fixed a setting in the virtual smtp server settings regarding relay specifying that this machine is on the list of accepted computers, I have gone into my gmail account and successfully sent myself an e-mail to this server, used the local machine's outlook to send myself an e-mail to the local machine from itself, however, when I try to send myself an e-mail in a C# application using either the System.Net or System.Web Mail namespaces, my gmail account never actually receives the e-mail, I have checked the spam folder...nothing, I have looked in the folder queue and the message is there which tells me something may be wrong with the relay but I cannot put my finger on it, I have set the domain to one that I can reach my server with from ANYWHERE, it's 5 miles long but we can thank rogers cable internet services for that later, Any ideas? Many thanks to those who answer, Dave

If you are saying you are using a application (IIS or whatever) on a server to connect to itself to send out bound messages, then here are a few things to try. #1 - Ensure that your SMTP virtual server is set to listen on all IP addresses. I saw once (don't remember if it was with Exchange 2003) that someone was using the IP of 127.0.0.1 to try to deliver mail but the admin had configured the virtual server to only listen on the real IP. Switching it back seemed to fix that. #2 - You can turn up the Exchange 2003 Message Transport diagnostic logging to maximum on all the sub-components to see if the email is getting to Exchange and then the Message Transport service is dropping it. #3 - If it doesn't look like Exchange 2003 is getting the message, then use the IIS SMTP diagnostics logging to see if you can find out why the SMTP service is not handing it to Exchange: http://support.microsoft.com/kb/303738 Good luck!