ssh_dh?

[Benny Pedersen]

Daniel Miller via dovecot skrev den 2018-12-16 23:30:
So...either there's an undocumented feature of SSH-over-IMAP (that's
> Dovecot - always on the cutting edge!) or someone had a coffee
> shortage during a coding session...

its std way of drinking coffee :=)

https://www.sidorenko.io/post/2014/02/secure-ssl-configuration-for-apache-postfix-dovecot/

make one for dovecot or reuse one from postfix