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

Results formail.ghostforbeginners.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2025-01-27T14:05:24.193	2025-01-27T13:06:53	2025-04-27T13:06:52	mail.ghostforbeginners.com	mail.ghostforbeginners.com	C=US, O=Let's Encrypt, CN=R11
2025-01-27T14:05:23.592	2025-01-27T13:06:53	2025-04-27T13:06:52	mail.ghostforbeginners.com	mail.ghostforbeginners.com	C=US, O=Let's Encrypt, CN=R11
2024-08-22T18:25:22.635	2024-08-22T17:26:51	2024-11-20T17:26:50	mail.ghostforbeginners.com	mail.ghostforbeginners.com	C=US, O=Let's Encrypt, CN=R10
2024-08-22T18:25:22.142	2024-08-22T17:26:51	2024-11-20T17:26:50	mail.ghostforbeginners.com	mail.ghostforbeginners.com	C=US, O=Let's Encrypt, CN=R10