Changing the mail hostnamePoint mail.example.com at your server in public DNS first. AutoSSL issues a matching certificate afterward; on a VPS, HELO and PTR must agree with the name you announce.Updated Aug 29, 2026
SSL on addon domains and mailMail TLS needs the hostname the client connects to on the certificate. AutoSSL issues each name after DNS points here. A web-only cert leaves Thunderbird warning on mail.example.com.Updated Aug 29, 2026