OS 2.1 is really required for extensive Internet usage and if you want to do anything fancy like IMAP, then you'll need the increased RAM of the 2100 (over the 2000). Simon Bell's Mail V is an excellent POP/IMAP client, but there is no SSL support in the Newton OS, so unfortunately Gmail is not an option. .Mac/Mobile Me doesn't require SSL, last I checked, but I'm not sure whether iCloud will or not. Some Newton users use Fastmail as they also don't require SSL.