What is SPF?

SPF (Sender Policy Framework) is an email-authentication standard that uses a DNS record to declare which mail servers are allowed to send email for your domain. When a receiving server gets a message claiming to be from you, it checks your SPF record to see whether the sending server is on that list.

How SPF works

You publish a TXT record on your domain listing the services permitted to send for it:

v=spf1 include:_spf.google.com include:amazonses.com -all

The receiving server looks up that record, checks whether the connecting server’s IP is authorized, and records a pass or fail. The trailing -allmeans “reject anything not listed.”

Why it matters

SPF is one of the three pillars of email deliverability, alongside DKIM and DMARC. If your SPF record is missing or wrong, mailbox providers may route your mail to spam — or reject it. When you send to a Devmailr inbox, the SPF result is surfaced as a verdict on the received message, so you can confirm your real send path passes. See testing SPF, DKIM, and DMARC.