email service, storage requirements, and 22gb of space

One of our remote sale force wants to receive email on his Blackberry.  OK, no big deal.  The problem is that  he wants to have *all* email on both his Blackberry, and his local in-house machine.  As far as I can tell, this requires a server-based email store.  Please correct me if I'm wrong on this point...this is a bit of an assumption, and any work-around for this is more than acceptable.

We use POP accounts for our in-house email, on our own server (hosted, dedicated).  The server has a 60gb drive with about 22gb unused, and the management does not want the additional expense of adding space, or creating a dedicated email server.  Given the high volume of email our company processes (sales force, in particular, IT to a lesser extent), my advice to management was a master/slave sort of configuration, where one device (BB) downloads only, while the other (local computer) downloads and deletes.  Still this does not necessarily mean every email will be available from both devices, and sent emails will only be available from the sending device.

My question is more a request for confirmation.  In this scenario, what is going to happen if email is allowed to be stored on the server?  What would be the effect of having one device delete email?  Basically, what are all the possible scenarios here, given the single server, and an in-house email account serving two devices?Start Free Trial