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

Results for_spf.eemsg3.mail.mil

Resolver

Location

TXT

Name	TTL	Value
_spf.eemsg3.mail.mil	2276	spf2.0/pra ip4:214.24.21.64/28 ip4:214.24.22.64/28 ip4:214.24.24.64/28 ip4:214.24.26.64/28 ip4:214.24.27.64/28 -all
_spf.eemsg3.mail.mil	2276	v=spf1 ip4:214.24.21.64/28 ip4:214.24.22.64/28 ip4:214.24.24.64/28 ip4:214.24.26.64/28 ip4:214.24.27.64/28 -all