nslookup

> set type=txt

> gmail.com

Server:        8.8.8.8

Address:    8.8.8.8#53

Non-authoritative answer:

gmail.com    text = "v=spf1 redirect=_spf.google.com"

Authoritative answers can be found from:

> _spf.google.com

Server:        8.8.8.8

Address:    8.8.8.8#53

Non-authoritative answer:

_spf.google.com    text = "v=spf1 include:_netblocks.google.com include:_netblocks2.google.com include:_netblocks3.google.com ~all"

Authoritative answers can be found from:

> _netblocks.google.com

Server:        8.8.8.8

Address:    8.8.8.8#53

Non-authoritative answer:

_netblocks.google.com    text = "v=spf1 ip4:64.233.160.0/19 ip4:66.102.0.0/20 ip4:66.249.80.0/20 ip4:72.14.192.0/18 ip4:74.125.0.0/16 ip4:108.177.8.0/21 ip4:173.194.0.0/16 ip4:209.85.128.0/17 ip4:216.58.192.0/19 ip4:216.239.32.0/19 ~all"

Authoritative answers can be found from: