In the context of a web server with HTTP, HTTPS, IMAPS, POP3S, SMTPS, SFTP and WebDav services, is it necessary to get a SSL certificate for the FQDN hostname of a server (example: something.example.com), if we never use the FQDN hostname for HTTPS (like: https://something.example.com)?
Can't we just install an SSL certificate for the "root" domain (like example.com) and use it for all secured services?