Here's the problem: The customer uses Outlook Express on their brand new Dell Dimension 4500S with XP Home. They can recieve their e-mail fine with their dial-up connection, but if they try to send an e-mail they get an error message stating "An unknown error has occurred. Protocol: SMTP, Port: 0, Secure (SSL): no, Error Number 0x800C013B". I've checked the SMTP settings and POP3 settings. Incoming (POP3) is port 110 and outgoing (SMTP) is port 25. I have no idea where it's getting the Port 0 from. There isn't any firewall software installed nor is the XP internet firewall enabled. Any ideas?