we have a pretty simple email and DNS infrastructure, but I can't figure out what our SPF record ought to be.
Our lone email server is in house, we do not route mail through our ISP.
We have one subdomain. Should I have an SPF record on the subdomain?
This is our current SPF record, which has worked well except for one thing. Our website has a contact form, and email sent to us from the contact form comes from another mail server. This server may be one of several at the webhost (all are on the same domain).
So, what should I change to reflect that mail from our webhost server farm is also valid?
"v=spf1 a mx ~all"