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

Results formail.sequas.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2023-07-01T00:53:25.811	2023-06-30T23:53:25	2023-09-28T23:53:24	stepsblings.com	*.sequas.com	C=US, O=Let's Encrypt, CN=R3
2023-07-01T00:53:25.714	2023-06-30T23:53:25	2023-09-28T23:53:24	stepsblings.com	*.sequas.com	C=US, O=Let's Encrypt, CN=R3
2017-02-02T13:51:53.387	2017-01-28T00:00:00	2017-04-28T23:59:59	sequas.com	mail.sequas.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2016-11-18T02:16:05.707	2016-11-13T00:00:00	2017-02-11T23:59:59	sequas.com	mail.sequas.com	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"