SSL error: wrong version number

Hello hello, when trying to enable POP3 polling a generic error appears in the UI: “sorry an error has occurred”. On checking the logs we see this:

OpenSSL::SSL::SSLError (SSL_connect returned=1 errno=0 state=error: wrong version number) /usr/local/lib/ruby/2.6.0/net/protocol.rb:44:in `connect_non

What does this mean? Any pointers to the meaning or possible resolution of this issue would be much appreciated!

Full log and screenshot below.

Message (4 copies reported)

OpenSSL::SSL::SSLError (SSL_connect returned=1 errno=0 state=error: wrong version number)
/usr/local/lib/ruby/2.6.0/net/protocol.rb:44:in `connect_nonblock'

Backtrace

/usr/local/lib/ruby/2.6.0/net/protocol.rb:44:in `connect_nonblock'
/usr/local/lib/ruby/2.6.0/net/protocol.rb:44:in `ssl_socket_connect'
/usr/local/lib/ruby/2.6.0/net/pop.rb:553:in `do_start'
/usr/local/lib/ruby/2.6.0/net/pop.rb:531:in `start'
/usr/local/lib/ruby/2.6.0/net/pop.rb:317:in `auth_only'
/var/www/discourse/lib/validators/pop3_polling_enabled_setting_validator.rb:39:in `authentication_works?'
/var/www/discourse/lib/validators/pop3_polling_enabled_setting_validator.rb:18:in `valid_value?'
/var/www/discourse/lib/site_settings/type_supervisor.rb:215:in `validate_value'
/var/www/discourse/lib/site_settings/type_supervisor.rb:140:in `to_db_value'
/var/www/discourse/lib/site_setting_extension.rb:349:in `add_override!'

Env

HTTP HOSTS: discuss.lightmeter.io

Any ideas? Still stuck on this

Hey! Did you fix it? I had a similar issue.
I was able to fix it by enabling TLS 1.2 in my mail server. I think discourse does not support SSL TLS1.3 while POP3 polling and that was causing the issue.
What service are you using for incoming mails?