Mail server related need help, please
 

I have two office 'A' and 'B'. My mail server located in Office 'A'. There are 20 mail user in office 'B'.
Office 'B' users used to pop their mail. I need a solution for office 'B' users that their local mail would not travel Office 'A' and they get their internal email without via Mail server.

Please help me?

You'll have to have some kind of MTA period. Mail won't be moved without the MTA to do it. You might want to build an inexpensive Linux box and run sendmail on it in office B. You can configure Sendmail to send local mail locally and then to send out the other mail to the other server. But, you'll have to have some kind of MTA to move the mail from one PC to another.