What is SPF?

Sender Policy Framework (SPF) is a DNS TXT record at your domain apex that lists which mail servers are allowed to send mail using your domain in the envelope sender (MAIL FROM / Return-Path).

What AuthDNS checks

• Whether a single v=spf1 TXT record exists at the apex
• Whether a terminal all mechanism is present (-all, ~all, etc.)

Example draft

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

Replace includes with whatever your mail providers document. Too many DNS lookups (the SPF 10-lookup limit) can break evaluation — keep records lean.

Run a DNS check