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

Results formail.linkmetool.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2018-01-01T20:10:11.779	2018-01-01T00:00:00	2018-07-10T23:59:59	sni201744.cloudflaressl.com	*.linkmetool.com	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO ECC Domain Validation Secure Server CA 2
2017-12-16T10:35:03.254	2017-12-16T00:00:00	2018-06-24T23:59:59	sni201744.cloudflaressl.com	*.linkmetool.com	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO ECC Domain Validation Secure Server CA 2
2017-12-06T19:30:23.357	2017-12-06T00:00:00	2018-06-14T23:59:59	sni201744.cloudflaressl.com	*.linkmetool.com	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO ECC Domain Validation Secure Server CA 2
2017-12-06T13:57:17.495	2017-12-06T00:00:00	2018-06-14T23:59:59	sni201744.cloudflaressl.com	*.linkmetool.com	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO ECC Domain Validation Secure Server CA 2