SMTP Relay Server is a SMTP server program for Windows that lets you
convert any Windows based PC into SMTP server. You are allowed to use
it either on a dedicated server or on a personal computer in the
background. It can be used along with any mailer or email program
working on the same computer or on a separate computer connecting to
SMTP Relay Server using TCP/IP protocol. Traveling laptop PC users
using different Internet Service Providers (ISP) on the go may use SMTP
Relay Server as a gateway SMTP server that either sends your messages
directly when possible or redirects them to other SMTP accounts if
direct sending is blocked by the current ISP. The email program you
already use for sending and receiving messages can easily be used along
with the server just by using the IP address "127.0.0.1" instead of
your current SMTP host. SMTP Relay Server offers you a lot of security
options to protect your machine from hacker attacks and filter SPAM.