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

Results forsecuremail.vansoc.va.gov

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2016-10-01T08:07:01.65	2012-05-04T20:11:14	2013-05-04T20:11:14	securemail.vansoc.va.gov	securemail.vansoc.va.gov	C=US, O=Cybertrust Inc, OU=Services, OU=PKI, CN=Cybertrust Public Issuing CA 1
2016-10-01T03:25:42.337	2012-05-04T20:02:10	2013-05-04T20:02:10	securemail.vansoc.va.gov	securemail.vansoc.va.gov	C=US, O=Cybertrust Inc, OU=Services, OU=PKI, CN=Cybertrust Public Issuing CA 1
2016-09-27T12:19:15.853	2012-05-04T20:08:52	2013-05-04T20:08:52	securemail.vansoc.va.gov	securemail.vansoc.va.gov	C=US, O=Cybertrust Inc, OU=Services, OU=PKI, CN=Cybertrust Public Issuing CA 1
2016-09-27T00:53:46.786	2012-05-11T20:05:30	2013-05-11T20:05:30	securemail.vansoc.va.gov	securemail.vansoc.va.gov	C=US, O=Cybertrust Inc, OU=Services, OU=PKI, CN=Cybertrust Public Issuing CA 1