POP3 Email Problem

Can anyone help me in finding the solution that why POP3 emails starts downloading again in Outlook Express from the beginning if the dial-up connection is dropped in between. Have configured Qpopper as well but still the problem persists.

The problems becomes severe and panic if there are large number of emails on RedHat Linux 7.2 server and the connection sometimes drops due to line problems.

I would be very thankful if someone gives the solution.