Dan Pollock pollock@theorem.ca writes:

I would like to move everyone onto more modern mail programs, but at the moment I have a couple of them that are stuck using very old software installed for them on work computers. The rest of my clients can connect on ports 993 and 995 without it being a problem.

You know best whether you want to take the risk of compromising passwords on your system (including compromised accounts using for spamming and blowing your mail reputation to smithereens), but I don't know whether your customers do. They may think they are only risking their Email, but it can be leveraged to also gain access to other authentication systems e.g. "Forgot password" feature.

You can suggest the installation of a SSL proxy for those holdouts that won't switch mail readers (stunnel even has support down to Win98).

https://www.stunnel.org/ports.html

These days, cleartext passwords over the network is just begging to be compromised.

Joseph Tam jtam.home@gmail.com