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

Results forwww.mail.pmogs.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2016-10-02T03:08:16.088	2010-05-28T20:27:36	2012-05-28T01:45:37	mail.pmogs.com	www.mail.pmogs.com	C=US, ST=Arizona, L=Scottsdale, O="Starfield Technologies, Inc.", OU=http://certificates.starfieldtech.com/repository, CN=Starfield Secure Certification Authority, serialNumber=10688435
2014-06-26T12:39:50.898	2014-06-19T17:03:35	2016-05-30T01:48:39	mail.pmogs.com	www.mail.pmogs.com	C=US, ST=Arizona, L=Scottsdale, O="GoDaddy.com, Inc.", OU=http://certs.godaddy.com/repository/, CN=Go Daddy Secure Certificate Authority - G2
2014-06-09T11:40:22.48	2014-05-30T01:48:39	2016-05-30T01:48:39	mail.pmogs.com	www.mail.pmogs.com	C=US, ST=Arizona, L=Scottsdale, O="GoDaddy.com, Inc.", OU=http://certs.godaddy.com/repository/, CN=Go Daddy Secure Certificate Authority - G2
2013-06-28T11:58:28.205	2013-06-18T17:42:53	2014-05-29T14:37:36	mail.pmogs.com	www.mail.pmogs.com	C=US, ST=Arizona, L=Scottsdale, O="Starfield Technologies, Inc.", OU=http://certificates.starfieldtech.com/repository, CN=Starfield Secure Certification Authority, serialNumber=10688435
2013-04-19T13:50:17.749	2012-05-29T14:37:36	2014-05-29T14:37:36	mail.pmogs.com	www.mail.pmogs.com	C=US, ST=Arizona, L=Scottsdale, O="Starfield Technologies, Inc.", OU=http://certificates.starfieldtech.com/repository, CN=Starfield Secure Certification Authority, serialNumber=10688435