Because of the current additional SAN limit of 100 by Let’s Encrypt, I don’t use “vanity” mail server addresses, e.g. mail.the-domain.com, instead I use the same mail server address for all the domains, e.g. mail.example.com.
The mailcow web GUI lists autodiscover.; _autodiscover._tcp. and autoconfig. as records that should be added.
It is not clear to me whether the autoconfig/autodiscovery features require HTTPS (hence an additional SAN).
When I don’t use “vanity” mail server addresses I don’t have to occupy more additonal SANs for these.
Can I omit these? Is HTTPS required for autoconfig/autodiscovery support?