What This Test Does

This is a one-click combined audit of the five things that decide whether mail to your domain works correctly. Each check is detailed enough to act on, with a deep-dive link to our dedicated tool if you want full diagnostics on any single check.

The 5 Checks Run

1. MX Records - does your domain have published mail servers? Single MX = single point of failure. Multiple MX = redundancy.
2. SPF - is a Sender Policy Framework record published, single, and within the RFC 7208 10-DNS-lookup limit? Multiple SPFs or over-limit = PermError = SPF fails.
3. DKIM - are common selectors publishing valid public keys? We test 22 common selector names used by major ESPs.
4. DMARC - is a DMARC policy published with at least p=quarantine or p=reject, plus rua= aggregate reporting?
5. Blacklist on MX IPs - are your inbound mail servers listed on Spamhaus ZEN, Barracuda, SpamCop, SORBS, or Mailspike?

How the Score Is Calculated

Each of 5 checks contributes 0-20 points. Pass = 20, Warning = 10, Fail = 0. Score range 0-100.

80-100 - strong deliverability foundation
50-79 - fixable issues; address them before scaling sending volume
0-49 - critical configuration problems; mail will be filtered or rejected

What This Test Does NOT Cover

A 100/100 score on this audit is necessary but not sufficient. These factors matter equally and need separate attention:

Sending IP reputation - your outbound IPs (different from MX IPs). Use our Blacklist Checker with your ESP's outbound IP.
List quality - bounces and spam-trap hits destroy reputation. Verify addresses before send.
Content quality - use our Spam Score Checker to test subject + body.
Engagement signals - opens, clicks, complaints. Built from real sending history.
Sender alignment - even with all records published, alignment between From: domain, DKIM d=, and SPF Return-Path must match.

Read the full deliverability playbook

Our sender-reputation guide covers the full picture - auth, lists, content, engagement, and the metrics that actually move inbox placement.

Read the sender-reputation guide

Frequently Asked Questions

Why does my score show DKIM as a warning even though I have DKIM configured?

We auto-test 22 of the most common DKIM selector names (selector1, google, k1, mandrill, sendgrid, etc.). If your ESP uses a custom selector outside our list, we won't find it and report a warning. Use our dedicated DKIM Checker with your specific selector to confirm.

My DMARC is set to p=none. Is that bad?

p=none is monitor-only - receiving servers report failures but still deliver spoofed mail. It's a fine starting point but should be temporary. After 30 days of clean reports, ramp to p=quarantine, then p=reject. We mark p=none as a warning, not a fail, because it does provide reporting visibility.

The blacklist check on MX IPs is clean but I still have delivery problems.

This audit checks INBOUND MX IPs - where mail to your domain arrives. If you're sending mail and addresses bounce or filter, the issue is your OUTBOUND sending IPs (different from MX IPs). Run our IP Blacklist Checker against the actual IP your ESP or self-hosted SMTP uses for outbound delivery.

Why is the test rate-limited to 5 per minute?

Each audit runs ~40 DNS queries (MX + SPF chain + 22 DKIM selectors + DMARC + 5 DNSBLs × 3 MX IPs). To stay friendly with Spamhaus and other DNSBL operators (who throttle high-volume queriers), we cap per-IP audit rate. For batch auditing across many domains, contact us for API access.

The pre-campaign deliverability checklist

Five steps, in order, before any significant send. Seed-inbox testers like Mail-Tester or GlockApps and this page's DNS audit answer different questions - use both.

1. Authentication. Confirm SPF covers every IP you actually send from, DKIM is published for your sending domain, and DMARC is set to quarantine or reject - a p=none policy monitors but protects nothing.

2. Blocklists. Check your sending IPs and domain against the major DNSBLs (Spamhaus ZEN, Barracuda, SURBL) - our blacklist checker covers 16 in one pass. Delist before sending, not after.

3. List hygiene. Verify the list, remove undeliverables, and route risky/catch-all rows into a lower-frequency sub-sequence instead of the main blast.

4. Seed test. Send to a seed list via Mail-Tester or GlockApps after cleaning, so the test reflects real send conditions - content, authentication, and list quality together.

5. Monitor and stop-loss. Watch Google Postmaster Tools and Microsoft SNDS during the send. If bounce rate passes 2%, stop and re-verify the segment before continuing.

Email Deliverability Test