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

Results forspf3.mailgrid.com.br

Resolver

Location

A

Name	TTL	Value
spf3.mailgrid.com.br	300	167.172.150.101DigitalOcean, LLC

Name	TTL	Value
spf3.mailgrid.com.br	300	v=spf1 ip4:54.39.64.71 ip4:54.39.64.70 ip4:142.44.198.150 ip4:142.44.144.180 ip4:142.44.146.110 ip4:158.69.209.105 ip4:158.69.109.135 ip4:158.69.5.233 ip4:198.100.158.33 ip4:18.230.185.31 ip4:51.222.173.17 include:spf_o.mailgrid.com.br -all