example.com. IN TXT v=spf1 a -all
What does this mean?
Every Internet domain name has a corresponding IP address.
If the domain name
example.com (use your domain name) is given to your IPAD-OS and the IPAD-OS is the place where all email from you will originate, answer YES to this question.
If your IPAD-OS has a different domain name like
mail.example.com then answer NO to this question.