POPWeasel - description from Softdepia.com:
Expand the abilities of your SMTP mail server... Collect mail from multiple POP accounts. Pass mail on to SMTP enabled servers like Lotus Notes/Domino and
MS Exchange/Exchange 2000. Command line driven for simple system integration. Easy to configure with our setup application. Powerful and flexible mail routing process.
Extensive logging capabilities to assist with problem solving. Superb administration utility allows rapid diagnostics.
POPWeasel is a "Free to try" program. You can download and try it for an evaluation period.