[Dovecot] imaps multiple domains proposal

[Jim Flowers]

FWIW, stunnel can be configured to run multiple instances (one per ip/domain)
each with its own certificates and services (pop3s, imaps, https, etc.)
connected to the appropriate ip:port (pop3, imap, http, etc.).  Very flexible
and user friendly as certificates are specific to the domain and users can
logon with just username (not username at domain.tld).

It also operates chroot but the certs are read at startup.