An email deliverability check reads your domain’s DNS to confirm SPF, DKIM, DMARC, and MX are present and valid — the four records mailbox providers use to decide inbox versus spam. Enter a domain above to see each record, a 0–100 score, and exactly what to fix.

What is SPF?

SPF (Sender Policy Framework) is a DNS TXT record listing which servers may send email for your domain. If a message comes from a server not on the list, receivers can reject or spam-filter it. A missing or wrong SPF record is the most common reason mail lands in spam.

What is DKIM?

DKIM (DomainKeys Identified Mail) adds a cryptographic signature to every message, with the public key published in DNS, so receivers can verify the mail genuinely came from your domain and was not altered in transit. DKIM is only fully confirmed by sending a signed test message.

What is DMARC?

DMARC (Domain-based Message Authentication, Reporting and Conformance) is a DNS TXT record at _dmarc.yourdomain.com that tells receivers what to do when SPF or DKIM fail — none, quarantine, or reject — and where to send reports. Without it, anyone can spoof your domain. A minimal record is: v=DMARC1; p=none; rua=mailto:you@yourdomain.com

What are MX records?

MX (Mail Exchange) records point your domain to the servers that receive its email. Without valid MX records, replies and inbound mail have nowhere to land — so a complete setup needs all four: SPF, DKIM, DMARC, and MX.

FAQ

How do I check if my domain has SPF, DKIM, and DMARC?

Enter your domain in the check above. It queries your live DNS and shows whether each record exists and is valid, plus a 0–100 score and a fix. There is also a keyless API: GET https://api.tinysend.com/v1/tools/deliverability?domain=yourdomain.com — no signup.

What does a good DMARC record look like?

Start with v=DMARC1; p=none; rua=mailto:you@yourdomain.com at _dmarc.yourdomain.com to monitor without affecting delivery, then tighten to p=quarantine or p=reject once your legitimate mail passes SPF and DKIM alignment.

Why is my email going to spam even with SPF set up?

SPF alone is rarely enough in 2026. Mailbox providers increasingly require DKIM and a DMARC policy that aligns with it. Run the check to see which of the four records is missing or misaligned — usually it is DKIM or DMARC.

Can an AI agent run this deliverability check?

Yes. Call GET https://api.tinysend.com/v1/tools/deliverability?domain= with no key, or use the check_deliverability tool on the tinysend MCP server at mcp.tinysend.com.