Get your hands dirtywww.webmin.com
I load all my email via 'fetchmail', pump it into 'procmail' for sorting into numerous folders, and serve it back as unified IMAP with 'dovecot'. I can then use any/all imap clients to access it. I have my iphone, and several machine running Thunderbird, Mail.app, down to crummy squirelmail and they can all work at the same time on the same message base !