[Exim] Flushing mails from a popbox to an SMTP host

Hi,

Can i flush mails already delivered to a pop account to an SMTP host ?

The reason I want to have this is coz I have a dial-up client using
exchange, and his line is very bad.
He would like to be able to check the mails mails waiting on my server from
a web-interface, delete any that is not needed
and have the rest to his exchange server.

Anyone with a script , or a better solution to his problem.

Rgds
TDN