Recieving mail from exchange users remotely

[billpc2]

I have a client who is using Exchange 2000 and their e-mail is hosted at their web-site, all of that works great. They've recently added some remote users who check e-mail over dial-up from out in the field, that works too. The problem is that the remote users cannot recieve e-mail from anyone in the office behind the Exchange server. Is there a simple way to resolve this problem? Any help would be greatly appreciated.