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

Results for_mail.level27.eu

Resolver

Location

TXT

Name	TTL	Value
_mail.level27.eu	600	v=spf1 ip4:91.208.211.0/24 ip4:91.223.195.0/24 ip4:185.3.216.0/22 ip4:193.104.8.0/24 ip4:194.32.152.0/22 ip4:194.247.160.0/23 ip4:195.225.164.0/22 ip6:2a02:5b40::/32 ip6:2a02:5b41::/32 ?all