Plenty of info in this thread...
http://www.amiga.org/forums/showthread.php?t=51352My input to it was...
"While not as sophisticated as the above, a simple way is BBS Server, which allows access from the Amiga via null modem serial cable through a winpc connected to the internet. Its a modem emulator, easy to set up, and works well. You can connect to BBS's, check email, chat etc. Download it from a real C=64 BBS, link below. Instructions on pdf are there also.
http://www.jammingsignal.com/leif/bbs/And cheers from the other Newcastle!