[rarestia]

I’m very active on IRC and NNTP. Telnet can be made secure with SASL. It’s a terrible protocol natively but like SMTP can be made functional.

[Cboldt]

-- Telnet can be made secure with SASL --

I don't think so, but it's your server. I lost a machine to a telnet attack, just having the port open and the service available. No login occurred, at least not through the usual auth mechanisms.