# SPF

SPF (Sender Policy Framework, RFC 7208) is a DNS TXT record in which a domain lists the servers allowed to send mail using its name, ending in a qualifier that says what to do with the rest.

Date: 2026-09-13

SPF, the Sender Policy Framework of RFC 7208, is a DNS TXT record beginning `v=spf1` in which a domain lists the addresses, hosts and included policies allowed to send mail using its name, and ends with an `all` term whose qualifier — `-all` fail, `~all` soft fail, `?all` neutral — says what a receiver should make of everything else. A receiver evaluates it against the envelope sender of each message.

## What Spaw answers

An email answer carries `has_spf`; a business domain without a record adds the `no_spf` weight of 10, while free providers are exempt because theirs is known. The domain endpoint adds `spf_all`, the effective qualifier, and `spf_lookup_count`, the number of DNS-querying terms the policy needs once `include:` and `redirect=` are followed — RFC 7208 allows ten, and a policy over that limit fails permanently at every receiver, which is the most common SPF fault there is.

## What it does not mean

SPF says who may send as the domain's envelope sender. It says nothing about the address a person sees in their mail client, which is what DKIM alignment and DMARC cover, and it breaks on forwarding, which is why a `-all` policy is not by itself a reason to expect delivery.

Reference: https://spaw.co/glossary/spf