My mail server is running at for example
mail.example.com and I have set an SPF record for
v=spf1 mx -all.
example.com also has its MX record set as well.
Now I have other domains which use the mail server to send emails, but their MX records are set to
Do I need to set each domain a SPF record like
v=spf1 mx -all or does it only relate to the mail server which is at mail.example.com?