The SMTP server that comes with IIS can be set up to serve only one IP - I usually set it up to serve only localhost on my WebConnect web server.

I put instructions for this on the following wiki:
http://www.west-wind.com/wiki/kb.wiki?wc~SMTPServerSetup

>Can I use WW Ipstuff to send email if my email server is setup to only send mail after verfication (use passwords) (stop the spammers)????
>
>I can send email fine as long as the server is open to relay.
>
>I use Imail which is a good email server. If I can not use it, what SMTP server can setup that is small, cheap and will only send email from ONE address or one IP????
>
>THANKS