オンラインツール
SPF Record Testing Tools https://www.kitterman.com/spf/validate.html?
cman.jp https://www.cman.jp/network/support/nslookup.html
nslookup コマンド
# nslookup -type=TXT *****.co.jp
Server: 192.168.0.1
Address: 192.168.0.1
Non-authoritative answer:
*****.co.jp text = "v=spf1 include:spf.*****.co.jp ~all"
Authoritative answers can be found from:
*****.co.jp nameserver = dns01.*****co.jp.
*****.co.jp nameserver = dns02.*****co.jp.
dns.*****.co.jp internet address = ***.***.***.***