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

Results forspf.firstwave.com.au

Resolver

Location

TXT

Name	TTL	Value
spf.firstwave.com.au	300	v=spf1 ip4:202.12.141.128/25 ip4:121.200.228.192/27 ip4:121.200.236.8/29 ip4:121.200.236.224/27 ip4:203.39.1.224/27 ip4:203.39.128.224/27 ip4:113.29.246.240/28 ip4:13.211.12.136/29 ip4:52.65.119.61/32 ip4:3.25.47.16/30 ip4:3.25.48.212/30 ip4:202.137.107.152/32 ~all