I have a similar setup. SCO OS/5 is my internet server and my network
contains two 95 boxes and 1 NT box. I also use sendmail on the SCO box.
However, I do not believe that you will get sendmail to deliver anything to
your 95 boxes! Instead, the 95 boxes will use SCO's POP server to retrieve
mail. This is easily set up on your 95 machine. Use the mail/fax icon on
the control panel. Then, when you go into Microsoft Exchange, you will
automatically get your mail. I am assuming here that you, like I, have
a TCP/IP connection between the machines.
As far as sending mail from the 95 boxes, no problem. Again, the setup
wizard for mail/fax will guide you.
This means that your 95 users will need accounts established on your SCO box
because they will need to let Exchange know the logonid and password.
Steve