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

Results forwm.spf.163.com

Resolver

Location

TXT

Name	TTL	Value
wm.spf.163.com	600	v=spf1 ip4:210.79.60.0/24 ip4:115.236.112.0/20 ip4:45.254.49.0/24 ip4:117.147.224.0/24 ip4:45.195.16.0/20 ip4:103.129.254.64/26 ip4:103.209.128.0/24 ip4:154.81.10.0/24 ip4:103.126.93.0/24 ip4:156.224.80.0/22 include:c.spf.ntesmail.com -all