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.

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    I think the most viable solution is going to look like a pair of IMAP and SMTP daemons that proxy the Gmail box from the Pi. In which case the only ‘retro’ aspect of this setup is going to be that the client that connects to that proxy happens to be running on an old device… Jul 31, 2022 at 14:34
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    I’m voting to close this question because while it is a Retrocomputing device, the real issue is encryption (or not) of email, which affects numerous devices, applications, etc. and not specifically RC. Jul 31, 2022 at 15:44
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    I forget whether GMail supports the right kind of TLS initiation, but one option could be using 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.
    – ssokolow
    Jul 31, 2022 at 15:53
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    @manassehkatz-Moving2Codidact there is a meta discussion about this at retrocomputing.meta.stackexchange.com/questions/1117/… Jul 31, 2022 at 18:24
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    @raffzahn the point of the meta post was to wonder if a question becomes off topic because some answers would be off topic. Just because I know of 2 possible answers (neither of which I have tried yet) doesn't mean they are the best answers. If I try them and they work, I will post them. Jul 31, 2022 at 19:24

1 Answer 1


Connecting an email client without SSL to a modern server requires some sort of SSL gateway on another machine. For example, under Linux you might run a command like

socat -v ssl:imap.gmail.com:993,end-close tcp4-listen:143,fork,reuseaddr &

You can then point your email client at the gateway machine.

It turns out that stunnel (as suggested) will do all of the above, and add SMTP authorisation, making it an ideal solution.

I have found I can also use a Bluetooth connection to an Android phone and run stunnel there.


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