Sender Policy Framework. A key component to Email security. # Synopsis It is a public [[DNS]] record that states who is allowed to send emails on behalf of your domain. Pretend an email is a letter. It has a 'to' field, and a 'from' field. I can write anything I want on those fields, and assuming I drop it off at a generic post office, nobody would be the wiser. Email is more like a parcel. As a parcel moves through the postal system, it is tracked and stamped from pickup to delivery by every facility it passes through. Someone could send me a parcel from my mother, but if it was sent from a warehouse in China, and never passed through her house, I'm not going to trust it. In this case, [[SPF]] is a public record of which warehouses in China you send parcels from, so that your recipient won't toss it out with distrust. # Further Reading If you'd like to dig deeper, have a further read at [[MX Toolbox]], [What is an SPF record](https://mxtoolbox.com/dmarc/spf/what-is-an-spf-record)