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

Results formail.agreementsoftware.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2024-09-19T23:09:35.007	2024-09-19T00:00:00	2025-09-18T23:59:59	mail.agreementsoftware.com	mail.agreementsoftware.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G2
2024-09-19T23:07:41.922	2024-09-19T00:00:00	2025-09-18T23:59:59	mail.agreementsoftware.com	mail.agreementsoftware.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G2
2020-02-22T09:32:31.464	2020-02-22T00:00:00	2021-02-22T12:00:00	agreementsoftware.com	*.agreementsoftware.com	C=US, O=DigiCert Inc, OU=www.digicert.com, CN=Encryption Everywhere DV TLS CA - G1