Would it be possible to add support for POP3 (non-s) (ie port 110).
On my server, discourse and the pop server are both on the same server, so there is no need to encrypt the session (anyone with access to the connection already has access to the data at either end). The POP3 server I use is a custom server that doesn’t require unix-level accounts and so is very safe (any security issue would compromise only a minimal permission account).
I added support for POP3 in discourse simply be editing app/jobs/scheduled/poll_mailbox.rb near line 43:
if SiteSetting.pop3s_polling_port.to_i != 110 Net::POP3.enable_ssl(OpenSSL::SSL::VERIFY_NONE) end
Basically, if the port is 110, don’t use SSL. Now obviously it would be better to have a UI switch for POP3/POP3s, but at least this got me working and proved that the change is trivial at the engine side.