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

Results forww25.smtp.webappsolution.org

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2024-12-04T20:26:17.087	2024-12-04T19:27:46	2025-03-04T19:27:45	ww25.smtp.webappsolution.org	ww25.smtp.webappsolution.org	C=US, O=Let's Encrypt, CN=R10
2024-12-04T20:26:16.835	2024-12-04T19:27:46	2025-03-04T19:27:45	ww25.smtp.webappsolution.org	ww25.smtp.webappsolution.org	C=US, O=Let's Encrypt, CN=R10
2024-09-02T09:45:47.628	2024-09-02T08:47:17	2024-12-01T08:47:16	ww25.smtp.webappsolution.org	ww25.smtp.webappsolution.org	C=US, O=Let's Encrypt, CN=R10
2024-09-02T09:45:47.445	2024-09-02T08:47:17	2024-12-01T08:47:16	ww25.smtp.webappsolution.org	ww25.smtp.webappsolution.org	C=US, O=Let's Encrypt, CN=R10