Free Tool

Email Deliverability Health Check

Most brands discover a deliverability problem through declining open rates — weeks after it starts. Enter your domain and get an instant A–F grade across SPF, DKIM, DMARC, blacklists, and MX records in 10 seconds.

What's Actually Blocking Your Emails

Is your SPF record letting spam through?

SPF tells inbox providers which servers are authorized to send email for your domain. A missing or too-permissive SPF record causes 15–30% of legitimate emails to be filtered. Most brands set it up once and forget it — then add a new ESP and break it.

Why Gmail targets your emails without DKIM

DKIM cryptographically signs every email from your domain. Without it, Gmail and Yahoo treat your emails as unsigned — and unsigned emails receive no trust credit. DKIM failure is the leading cause of B2B and eCommerce emails landing in the Promotions tab.

Who's sending email as your domain right now?

DMARC answers that question. It tells inbox providers what to do when an email fails SPF or DKIM — and gives you daily reports of every IP sending mail as your domain. Brands without DMARC are the easiest targets for phishing attacks that erode sender reputation.

A single blacklist listing can block thousands of emails instantly

When your domain or sending IP appears on Spamhaus, Barracuda, or SORBS, inbox providers reject or filter your mail at the gateway — before recipients ever see it. Listings can appear within hours of a complaint spike. This check queries 50+ lists simultaneously.

Why We Built This Tool

InboxEagle monitors authentication records for 2,000+ brands. The most common issue we see: a team adds a new ESP to their stack, the SPF record hits the 10-lookup limit, and inbox rates drop weeks later without anyone connecting the cause. This check makes that detection instant — so you catch it before it costs you.

What Goes Wrong Without This

Without SPF, DKIM, and DMARC alignment, ISPs can't cryptographically verify you're authorized to send email as your domain. Gmail and Yahoo both treat unauthenticated emails with zero trust — they skip the inbox entirely. A single blacklist listing can block thousands of emails at the gateway before recipients ever see them.

Who This Tool Is For

E-commerce & DTC Brands

Shopify and Klaviyo senders sending 50K–5M emails/month who add new ESPs and break SPF records without realizing it.

Email Marketing Agencies

Teams managing 5–50 client domains who need fast per-client audits without logging into each ESP separately.

B2B SaaS & Outbound Teams

Sales and marketing teams running sequences in HubSpot or Outreach where one broken authentication record stalls all cadences.

Frequently Asked Questions

What does the Email Deliverability Checker test?
This tool checks your domain's authentication records (SPF, DKIM, DMARC), MX configuration, and blacklist status across 50+ lists. It combines multiple checks into a single A–F grade so you can see your overall email security posture in seconds.
How often should I check my domain?
Run this check whenever you add a new ESP, rotate authentication keys, or notice a sudden drop in open rates. For ongoing monitoring, InboxEagle checks these records daily and alerts you the moment something breaks.
What does a 'D' or 'F' grade mean?
A D or F grade signals significant deliverability risk. Missing SPF or DMARC records means ISPs can't verify your emails are legitimate, which triggers spam filtering or outright rejection at the gateway. Blacklist listings have the same effect — a single listing can block emails at Gmail, Outlook, and Yahoo.
Do I need an InboxEagle account to use this tool?
No. This tool is completely free and requires no account or sign-up. InboxEagle provides it as a standalone resource for email marketers, developers, and agencies.

Daily Deliverability Changes. Your Check Doesn't.

This report is a snapshot. InboxEagle monitors your SPF, DKIM, DMARC, blacklist status, and inbox placement rate daily — and alerts you within minutes when something breaks. 2,000+ brands use it to maintain a 97.3% average inbox rate on 248M emails per month.

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