front end/back end

We are currently running on 1 Exchange 2000 server. WE have 150 internal users. We also have over 12000 “reps” that have an emailaddress@ourdomain.com. These 12000
reps never connect to our server and do not have
mailboxes on our server. Anyemail sent to
rep1@ourdomain.com (for example) gets forwarded to an external email address. Our single Exchange server is having a hard time trying to keep up forwarding out email to the 12,000 reps and also trying to handle our internal
email. My question is: If I set up a front end/back end topolgy and create a storage group on “BackEnd A” for our internal users, can I
make the front end server send all of the mail for the 12000 external users through “BackEnd B”?