AOX & iOS 18 not working

[Mykel]

Is it just me? Encountering on AOX servers both with paid SSL certs, and 
Let's Encrypt.

Tried with 18.0 and 18.1b6 & b7. Always the same error.
Seems if you use TLS on 143 it's okay...ish.


(Relevant query: does anyone have experience running IMAPS/SMTPS proxies 
in front of AOX? haproxy? stunnel? dovecot? nginx? Any advice?)