SMTP Email Proxy for Cold Email Outreach|All updates
DNS & auth

Free SPF Lookup

Analyse Sender Policy Framework records for any domain.

01 · Definition

What is spf lookup?

An SPF lookup — or SPF record check — reads the Sender Policy Framework record published as a TXT record on your domain. SPF tells receiving mail servers which IPs and hostnames are allowed to send mail using your domain in the envelope sender. When a receiver sees a message claiming to be from noreply@yourdomain.com, it does an SPF lookup on yourdomain.com and decides whether to accept, soft-fail or reject.

The tool above resolves the domain's TXT records, locates the v=spf1 entry, and displays the raw record alongside the final qualifier (-all, ~all, ?all) and a count of the direct DNS-lookup-consuming mechanisms. Read the SPF lookup guide for a full walkthrough of SPF record syntax, common errors, and how to interpret the results.

02 · Process

How it works

  1. 1Query the TXT records.Resolve yourdomain.com for TXT records and find the one starting with v=spf1. There must only be one.
  2. 2Parse every mechanism.Split the record into its components: ip4:, ip6:, include:, a, mx, exists:, redirect: and all. The tool counts any mechanism that triggers a further DNS query — include:, a, mx, exists:, ptr: and redirect: — toward the RFC 7208 limit of ten.
  3. 3Count DNS lookups.RFC 7208 caps the chain at 10. Going over triggers a permerror and receivers will treat the message as if SPF doesn't exist — exactly the case attackers want.
  4. 4Read the final qualifier.-all rejects unauthorised senders. ~all soft-fails (commonly junk-foldered). ?all and +all effectively disable SPF and should never appear in production.

03 · Risk

Why it matters

SPF is one third of the modern email-authentication baseline (SPF, DKIM, DMARC). Without it, any sender can spoof your domain into the inbox. With it misconfigured — too many lookups, missing senders, an over-permissive qualifier — the protection is theatre, not real.

For regulated firms, an SPF that silently fails is a compliance issue, not just a deliverability one. Mailbox providers downgrade unauthenticated mail to spam, the customer never sees it, and the firm has no audit trail of what was actually delivered.

19,766 financial promotions amended or withdrawn
UK FCA enforcement actions, 2024 — a 97.5% increase from 2023.

04 · Use cases

Common ways to use this tool

  • Pre-launch audit. Before a new sending domain goes live, confirm SPF is published and within the lookup limit.
  • Vendor onboarding. When you add a new ESP or transactional provider, verify their include: string is present and the chain didn't push you over 10 lookups.
  • DMARC rollout. Verify SPF alignment matches your DMARC policy direction — start at p=none, then move toward p=quarantine and p=reject with confidence.
  • Spoofing investigation. When customers report phishing claiming to come from your domain, an SPF lookup confirms whether the attacker's IPs would pass or fail.
  • Mergers and migrations. Two firms combining brands need to consolidate sending infrastructure without dropping any legitimate sender on day one.

05 · Interpretation

What to check in the result

The tool returns four things — read them in this order:

  • Lookup count under 10. If the count is at or above 10, SPF is failing for some receivers right now. Trim or flatten include: chains.
  • Single record. If you see two records starting v=spf1, SPF will permerror immediately. Merge them.
  • No +all or ?all. Either qualifier accepts unauthorised senders. Move to ~all while learning, -all in production.
  • Every legitimate sender represented. Marketing ESPs, transactional providers, billing systems, payroll, calendar invites — each needs its own include: or IP. Missing senders silently lose mail.

Frequently asked

Questions about this tool

Copyright © 2026 - Jonah and Associates Pty Ltd