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

Results forwhm2-test.dev.mailchannels.net

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2025-07-23T16:02:41.898	2025-07-23T00:00:00	2026-08-21T23:59:59	*.dev.mailchannels.net	*.dev.mailchannels.net	C=US, O=Amazon, CN=Amazon RSA 2048 M02
2021-07-29T02:57:09.873	2021-07-29T00:00:00	2021-10-27T23:59:59	whm2-test.dev.mailchannels.net	whm2-test.dev.mailchannels.net	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"
2021-07-29T02:57:08.841	2021-07-29T00:00:00	2021-10-27T23:59:59	whm2-test.dev.mailchannels.net	whm2-test.dev.mailchannels.net	C=US, ST=TX, L=Houston, O="cPanel, Inc.", CN="cPanel, Inc. Certification Authority"