What is an SPF Record?

An SPF (Sender Policy Framework) record is a DNS TXT record that lists all the mail servers authorised to send email on behalf of a domain. When a receiving server gets an email, it checks the sender's IP address against the domain's SPF record to verify the email is legitimate.

A typical SPF record looks like: v=spf1 include:_spf.google.com ~all — the ~all at the end means any other server is a soft-fail (suspicious). Use -all for hard-fail (reject).