My Psion 5mx is connected to the Internet via the built in TCP stack, and serial cable to a raspberry pi running a PPP server. The Psion message suite has an email client which will connect via POP3 and SMTP. I have added a plug in to also allow IMAP access.
There are few email providers who support unencrypted POP3 and SMTP access.
How could I connect the Psion email client to a secure SMTP or IMAP server?
Any solution is welcome, including another email client, an email server on the Pi end of the link or even, God forbid, Java.
stunnel
to terminate the TLS at the Pi, leaving ports that, when connected to by the Psion using unencrypted protocols, connect to GMail using encrypted protocols. If it works, it'd probably be simpler than setting up a full-blown application-layer proxying setup. That's basically what I did to hack around Pidgin's lack of a "This TLS-only IRC server is supposed to be self-signed. Stop prompting for confirmation whenever the network hiccups" checkbox.