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

Results forwebmail.webrserver.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-09-19T05:22:36.802	2020-09-19T04:22:36	2020-12-18T04:22:36	*.webrserver.com	*.webrserver.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-19T05:22:36.485	2020-09-19T04:22:36	2020-12-18T04:22:36	*.webrserver.com	*.webrserver.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-07-04T22:55:03.24	2020-07-04T00:00:00	2020-10-02T23:59:59	webrserver.com	webmail.webrserver.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2020-07-04T22:55:02.797	2020-07-04T00:00:00	2020-10-02T23:59:59	webrserver.com	webmail.webrserver.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2019-12-09T19:49:18.975	2019-12-09T00:00:00	2020-03-08T23:59:59	webrserver.com	webmail.webrserver.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2019-12-09T19:49:04.436	2019-12-09T00:00:00	2020-03-08T23:59:59	webrserver.com	webmail.webrserver.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"