proxy cpanel domains like cpanel.domain.com, whm.cdomain.com etc. and let's encrypt
I plan to migrate from DirectAdmin to cpanel, and I would like to know if is it possible to secure cpanel proxy subdomains like cpanel.domain.com, whm.domain.com and webmail.domain.com by free Let's encrypt certificate or do I need to buy wildcard one? When I checked last time (about 6 months ago I was unab;e to do that and I cannot secure exim, dovecot and FTP services by let's encrypt. Can anyone tell me if it is possible now? If not can anyone recommend cheapest wildcard SSL possible?