Free tool
Email deliverability checker
Enter a domain and see, in seconds, whether its email is set up to reach the inbox. We check SPF, DMARC, DKIM and MX and score it 0-100 — with exactly what to fix.
Checks public DNS only. DKIM uses common selectors — a custom selector may not be detected.
Why these four records decide the inbox
A cold or marketing email can be perfectly written and still land in spam if the sending domain isn't authenticated. SPF lists who may send for your domain, DKIM cryptographically signs your mail, DMARC tells receivers what to do when checks fail, and MX shows the domain can receive replies. Get all four right and receivers treat you as a legitimate sender — the single biggest lever on deliverability.
Reading each result
SPF. The common failures are having two SPF records (receivers treat that as invalid and ignore both) and exceeding the ten-lookup limit by chaining include: statements for every tool you have ever tried. Both look fine in a DNS panel and fail silently at the receiver. The deliverability guide below covers the flattening options.
DKIM. A missing DKIM is obvious; a present-but-broken one is worse, because mail still leaves and still fails verification. If you rotate sending platforms, the old selector usually stays behind and the new one never gets published. A rotated selector that was never published is the usual culprit.
DMARC. Publishing p=none is not a formality — it is the record receivers look for, and without it Google and Yahoo treat bulk senders as unauthenticated. Start at p=none, read the reports for a few weeks, and only then tighten. Moving to quarantine or reject before the reports are clean blocks your own mail.
MX. A sending domain that cannot receive mail is a red flag to filters and a dead end for anyone who replies. If you send from a subdomain, it still needs somewhere for bounces and replies to land.
What a clean result does and does not prove
All four green means receivers can verify you. It does not mean your mail reaches the inbox — authentication is the entry ticket, not the seat. Reputation, complaint rate, sending volume and content all sit on top of it, and a domain with perfect records can still be filtered if it burned its reputation last month.
This check also reads only what your domain publishes. To see what actually happens to a real message in transit — whether the signature survived, whether alignment held — send one to the spam test. The two checks answer different questions and are worth running together.
Fix order that saves time
If several records are wrong, repair them in this sequence: SPF first (it is the most commonly broken and the cheapest to fix), then DKIM, then DMARC last — a DMARC policy is only meaningful once the two mechanisms it references are passing. Publishing an enforcing DMARC policy before SPF and DKIM are clean is the fastest way to block your own legitimate mail. Give DNS changes time to propagate before re-testing, and expect a warmed domain to need a few days before receivers act on the new state. The deliverability guide covers the whole path.
Frequently asked questions
What does the deliverability checker test?
It reads your domain's public DNS and checks the four records that decide whether cold and marketing email lands in the inbox: SPF, DMARC, DKIM and MX. You get a 0-100 score and a specific fix for anything weak.
Is it free?
Yes — free and no signup. The check runs in your browser against public DNS.
Why does deliverability matter for cold email?
Even a perfect message fails if the sending domain isn't authenticated. SPF, DKIM and DMARC tell receivers your mail is legitimate; without them, campaigns land in spam and burn the domain.