Hi, One of our customers has an Exchange 2003 server and he wants to use it to send email through our SMTP (a non-exchange server). Our SMTP server requires "SMTP Authentication", which requires him to do the necessary login with a user name and password as per standard "SMTP Auth". What should he do in his Exchange Server so that it can send email through our non-Exchange mail server? The two servers are not local to each other on a LAN and there is no Netbios or "Client for Microsoft Networks" or "Windows Domain" or "Active Directory" connection between the two. The only connection between them is standard SMTP over the Internet, TCP/IP. TIA and best regards Mike