I am adding email sending to my Tomcat/Spring web app, and
i have read all the docs and samples, and articles i could find on JavaMail
but i have yet to locate a description of the set of valid formats
for the "host" property, only the obvious example.

The obvious case of "smtp.domain.com" for an external internet
smtp server, i get. I have not dealt with network programming before.

But my web app is for use ONLY on an intranet (LAN) inside
a customer firewall, and i haven't found any examples for this case.

Can i use a IP address instead of a url, like "" ?
or can i just use a the "host name" of the local server system running
the smtp server i.e. String host = "fooserv1";

If a plain host name can be used, what configuration has to be done
on the server running my web app Tomcat instance so it can resolve
the host name. ( my customer is running Tomcat on a virtual host
under Windows XP Pro )