Using Email Facility Through a VB Form (Urgent)

Hello Experts,

See the thing is I have to mail the data of a form on an email.
The application is a network application running on Winnt Server 4.0 and WinNT/98/2000 clients.
The Internet is available except on server offcourse, through Proxy and are behind some firewalls.
This much I know becuase they can't FTP or Browse from the nodes but can use facilties like  MSN/ICQ on nodes. So it's sure that there are some settings in Proxy/IIS/and some firewalls.

But the Client told me that all NODES are capable of fetching/sending emails just as they use MSN and ICQ, so mailing will not be a problem I guess.
Mails System being used on all is Microsoft Exchage.

Now the question is how to do Mailing Through VB from using on the theory of Microsoft Exchange.
Some component is there or some library, I don't know. Please tell me which component has to be used here for this facility in VB

Please see that since the time is very less and I don't want me to involve trouble, tell me the Component/Libarary which works on the basis of Microsoft Exchange only.

This I asked you becuase, As I don't know what is the difference between Outlook Express/Microsoft Outlook /Microsoft Exchange. If possible please also tell me, are they all using different different messaging sytem or Techniques or what is dfference in fetching mails through three.

Best Regards
Austin