It can be anything! An apex, subdomain, or even a URL.

Results forwww.mail.cerebraltech.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-04-09T15:23:17.452	2019-04-09T00:00:00	2021-04-22T23:59:59	mail.cerebraltech.com	www.mail.cerebraltech.com	C=GB, ST=Greater Manchester, L=Salford, O=Sectigo Limited, CN=Sectigo RSA Domain Validation Secure Server CA
2019-04-09T15:23:02.135	2019-04-09T00:00:00	2021-04-22T23:59:59	mail.cerebraltech.com	www.mail.cerebraltech.com	C=GB, ST=Greater Manchester, L=Salford, O=Sectigo Limited, CN=Sectigo RSA Domain Validation Secure Server CA
2014-07-12T13:04:29.803	2014-04-24T00:00:00	2019-04-23T23:59:59	mail.cerebraltech.com	www.mail.cerebraltech.com	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=PositiveSSL CA 2