POPBeamer - description from Softdepia.com:
POPBeamer is an inbound POP3 and IMAP router for Microsoft Exchange. POPBeamer collects messages from an unlimited number of POP3 or IMAP accounts and routes them to your Exchange server.
Every version of Exchange server including
Small Business Server 4.x and Exchange 2000
Any ISP's POP3 or IMAP server, even the older ones,
that do not support the Received for: header line
Dial-up, dial-up routers, ADSL and leased-line connections to the Internet
Any SMTP server like Exchange, Lotus Notes and Novell GroupWise
Proxy that support the SOCKS protocol like WinGate or ISA Server
MIME and UUENCODE messages, even with various Western and
Eastern European languages
POPBeamer is a "Free to try" program. You can download and try it for an evaluation period.