Can someone point me to a basic sendmail configuration that I can use which will force all email software to authenticate to the server, and send all email as from that server?

So if I have 47 people using Outlook inside my network, 5-7 using Outlook out on the internet, 12-15 people using other email software both locally and out on the net, they will all send messages as from my server, and can only send email if they successfully authenticate to the server?

- Mist