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

Results for*.lunchmail.se

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-08-09T22:16:43.203	2020-08-09T21:16:42	2020-11-07T21:16:42	*.lunchmail.se	*.lunchmail.se	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-08-09T22:16:43.203	2020-08-09T21:16:42	2020-11-07T21:16:42	*.lunchmail.se	*.lunchmail.se	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-08-09T22:16:43.043	2020-08-09T21:16:42	2020-11-07T21:16:42	*.lunchmail.se	*.lunchmail.se	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-08-09T22:16:43.043	2020-08-09T21:16:42	2020-11-07T21:16:42	*.lunchmail.se	*.lunchmail.se	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-08T19:16:51.333	2020-06-08T18:16:50	2020-09-06T18:16:50	lunchmail.se.fasterminds.net	*.lunchmail.se	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-08T19:16:51.333	2020-06-08T18:16:50	2020-09-06T18:16:50	lunchmail.se.fasterminds.net	*.lunchmail.se	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-08T19:16:51.037	2020-06-08T18:16:50	2020-09-06T18:16:50	lunchmail.se.fasterminds.net	*.lunchmail.se	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-08T19:16:51.037	2020-06-08T18:16:50	2020-09-06T18:16:50	lunchmail.se.fasterminds.net	*.lunchmail.se	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3