My mail server is running at for example mail.example.com
and I have set an SPF record for example.com
using 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 mail.example.com
.
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?