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

Results formail.bnry.de

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2022-09-03T22:04:17.983	2022-09-03T21:04:17	2022-12-02T21:04:16	mail.bnry.de	mail.bnry.de	C=US, O=Let's Encrypt, CN=R3
2022-09-03T22:04:17.783	2022-09-03T21:04:17	2022-12-02T21:04:16	mail.bnry.de	mail.bnry.de	C=US, O=Let's Encrypt, CN=R3
2022-07-05T21:52:43.248	2022-07-05T20:52:42	2022-10-03T20:52:41	mail.bnry.de	mail.bnry.de	C=US, O=Let's Encrypt, CN=R3
2022-07-05T21:52:42.699	2022-07-05T20:52:42	2022-10-03T20:52:41	mail.bnry.de	mail.bnry.de	C=US, O=Let's Encrypt, CN=R3
2022-05-06T11:42:57.282	2022-05-06T10:42:56	2022-08-04T10:42:55	mail.bnry.de	mail.bnry.de	C=US, O=Let's Encrypt, CN=R3
2022-05-06T11:42:56.581	2022-05-06T10:42:56	2022-08-04T10:42:55	mail.bnry.de	mail.bnry.de	C=US, O=Let's Encrypt, CN=R3