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

Results forspf.us-east.atmailcloud.com

Resolver

Location

TXT

Name	TTL	Value
spf.us-east.atmailcloud.com	60	v=spf1 ip4:167.179.24.0/24 ip4:3.225.135.164 ip4:3.226.116.164 ip4:3.226.13.77 ip4:34.195.55.106 ip4:34.235.240.234 ip4:3.91.212.73 ip4:52.45.247.67 ip4:52.4.9.86 ip4:54.160.229.207 ip4:54.82.52.103 -all