Question
Will AutoSSL cover mail.domain.tld when domain.tld uses a non-AutoSSL certificate?
Answer
Since the mail.domain.tld subdomain is added as an alias in a domains VirtualHost configuration, AutoSSL will not cover the mail.domain.tld subdomain if the primary domain uses a non-AutoSSL certificate. To use AutoSSL for mail.domain.tld, you can add it as a subdomain in cPanel >> Subdomains and then run AutoSSL.