Run live DNS TXT lookups against your domain in seconds. Detect broken SPF lookups, missing DKIM keys, or weak DMARC policies before sending cold emails.
Gmail and Yahoo require full SPF, DKIM, and DMARC authentication for cold outbound senders. Missing records lead to high bounce rates and immediate spam placement.
Lists IP addresses and authorized servers permitted to send email on behalf of your domain. Prevents spammers from spoofing your sender address.
Attaches an encrypted digital signature to outgoing mail headers. Receiving mail servers verify the public key in your DNS to confirm authenticity.
Defines the action receiving mail servers take when SPF or DKIM fails (quarantine or reject). Essential for maintaining long-term sender score.
SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) are the three foundational email authentication protocols. SPF defines which mail servers can send on your behalf, DKIM cryptographically signs your messages, and DMARC tells receiving servers how to handle emails that fail SPF/DKIM checks.
Major email providers like Gmail, Yahoo, and Outlook enforce strict authentication rules. Unauthenticated or misconfigured emails are flagged as spam, rate-limited, or blocked outright to protect users from phishing and domain spoofing.
Enter your domain name (and optional DKIM selector). Our tool performs live DNS TXT lookups against your domain, extracts the SPF, DKIM, and DMARC records, validates them against RFC specifications, points out misconfigurations, and gives you actionable plain-English fixes.
A DKIM selector is a string used to identify your public DKIM key record in DNS (e.g., 'google' for Google Workspace, 'selector1' for Microsoft 365, or 'k1' for Mailchimp). If you leave it set to 'google', we check the default Google Workspace selector, but you can enter your custom provider selector.
The SPF specification (RFC 7208) limits DNS lookups to a maximum of 10. Mechanisms like 'include:', 'a', 'mx', and 'redirect' trigger lookups. If your SPF record exceeds 10 lookups, receiving mail servers reject it with a PermError. You can resolve this by consolidating includes or using SPF flattening.
Yes. This tool is 100% free with no login required. You can check any domain instantly, view detailed failure logs, copy fixes, and share results via a unique URL.
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