SMTP doubt

Hi All,

I have a unix box which is in a network with windows machine, I am able to send the mails to the user id's with in the unix box. I dont have Internet connection for this box, so I am not able to test if it can send mails to external network or not?

I want to know, if SMTP is already configured and due to lack of internet connection I am not able to send emails, or SMTP is not at all configured?

if SMTP is not configured, how should I do it?

Here the problem is Unix box and Windows XP machine are in a network, I cannot give the internet connection to Unix box because of security constraints, I can give the internet connection to windows machine, if I have the internet on Windows, can I send mails from unix box to external networks?

Please help me in this, its a urgent requirement.

Thanks in advance.
Balaji