Free deliverability test
Send a real email. See exactly how it checks out.
Get a one-time test address, send it any email from the account you actually use to send mail, and get a graded breakdown back in real time.
What this test actually checks
When your email arrives, we read the raw message directly and run a real DKIM-Signatureverification against it — canonicalizing the signed headers and body per RFC 6376, fetching the public key your domain published in DNS, and cryptographically checking the signature. A message that's been altered in transit, or signed with a key that doesn't match what's published, is caught here.
Alongside that, we check whether your sending domain publishes SPF and DMARC records at all, and whether the DKIM signing domain aligns with your visible From: address — the alignment check DMARC actually relies on. What we can't do from here is evaluate the live SPF result for this exact message, since that depends on the sending IP, which isn't available to us on this platform.
Common questions
What actually happens when I send to the test address?+
The message arrives at a Cloudflare Email Worker we control, which cryptographically verifies any DKIM signature on the message against the public key your domain has published, and separately checks whether your domain publishes SPF and DMARC records. Nothing is forwarded anywhere and the address is single-use.
Why doesn't this check SPF the same way my mail server does?+
A live SPF check requires knowing the IP address the message was actually sent from, and the platform we receive test messages on doesn't expose that to us. So this checks whether your domain has a valid SPF record published at all — the same setup-level check as our standalone SPF checker — rather than a live pass/fail on this specific message.
Is the DKIM check a real cryptographic verification?+
Yes. We parse the actual DKIM-Signature header on your message, canonicalize the headers and body exactly as RFC 6376 specifies, fetch your domain's public key from DNS, and verify the signature against it. A tampered or invalid signature is genuinely detected, not assumed.
Does this simulate spam filters like mail-tester or similar tools?+
No — this focuses specifically on authentication (DKIM signature validity, SPF/DMARC presence), not spam-content scoring, blocklist checks, or inbox-placement prediction. Use our blacklist checker alongside this for a fuller picture, and treat this as one input into deliverability, not a full simulation.
How long is my test address valid?+
It's meant for one message, sent right after you get it. Results are stored for 24 hours so you have time to review them, then they're automatically deleted.
I sent the email but nothing happened. What went wrong?+
Double-check you sent to the exact address shown, including the test- prefix — a typo in the local part means the message goes nowhere useful. Delivery is usually near-instant, but can occasionally take a minute or two depending on your outgoing mail server.
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