Gets or sets the name of the SMTP relay mail server to use to send e-mail messages. Recommended alternative: System.Net.Mail.
Assembly: System.Web (in System.Web.dll)
If your local SMTP server (included with Windows 2000 and Windows Server 2003) is behind a firewall that blocks any direct SMTP traffic (through port 25), you will need to find out if there is a smart host available on your network that is allowed to relay SMTP messages to the Internet.
A smart host is an SMTP server with the permissions to relay outgoing e-mail messages directly to the Internet from internal SMTP servers. A smart host should be able to simultaneously connect to both the internal network and the Internet in order to work as the e-mail gateway.