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

Results forwww.mail.sutton.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-01-27T01:13:09.621	2014-03-06T21:19:22	2016-03-11T08:56:22	mail.sutton.com	www.mail.sutton.com	C=US, ST=Arizona, L=Scottsdale, O="GoDaddy.com, Inc.", OU=http://certs.godaddy.com/repository/, CN=Go Daddy Secure Certificate Authority - G2
2016-09-25T03:23:18.147	2010-03-02T20:17:56	2012-03-11T08:56:22	mail.sutton.com	www.mail.sutton.com	C=US, ST=Arizona, L=Scottsdale, O="GoDaddy.com, Inc.", OU=http://certificates.godaddy.com/repository, CN=Go Daddy Secure Certification Authority, serialNumber=07969287
2013-05-02T12:12:17.879	2012-03-08T04:12:33	2014-03-11T08:56:22	mail.sutton.com	www.mail.sutton.com	C=US, ST=Arizona, L=Scottsdale, O="GoDaddy.com, Inc.", OU=http://certificates.godaddy.com/repository, CN=Go Daddy Secure Certification Authority, serialNumber=07969287