Here is the current setup we have :

1.- Server :
Windows 2000 Server
DNS Server, DHCP Server, Proxy & NAT functional
ASDL Internet connection, shared over network (WinPoet dialer).

2.- Clients (15) :
Windows 98Se
Network used for three things:
1.- Internet access (Explorer, RealPlayer, MS Messenger)
2.- Internal eMail (Outlook 2000)
3.- Sharing of files.
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Is it possible to change to Linux (server only) and maintain full functionality of what I have described above?

Thank you..

absolutely
 

YES

Thank you.

Am I correct in assuming that I should use sendmail for the internal email?

that is an option
 

Sendmail is an option. There are others. Check out http://www.linuxapps.com under the MAIL section for more.

There are alternative mail servers there and plenty of add-ons for sendmail.

check this out...
 

Cool, thank you very much. I'll get to work convincing people right away.