Redirect-pop3

["Andrea Bencini" <andrea.bencini@tin.it>]

I have firewall (iptables) in my network (10.100.0.0/24) with iface eth0 in
local network and eth1 in external network (Internet).
eth0-->10.100.0.1-->default gateway for my local network.
My clients download mail (pop3).
I would like install p3scan into linux server (10.100.0.250) in my network
. This package listens on 8110 port and scans e-mails with clamav.
Without changing any configuration on my clients, the firewall should
redirect all mail download requests (pop3) to p3scan (port 8110); after
p3scan will download mails, will controll them and will deliver them to the
clients.
Other info:
Kernel-2.6
iptables-1.3.0
Which are the rules that I must implement on the firewall?
Thanks
Andrea