DKIM Checker

Email authentication is critical for protecting your domain's reputation and ensuring your messages reach their intended recipients. A DKIM checker helps you verify that your DomainKeys Identified Mail records are properly configured, preventing spoofing and improving email deliverability. Whether you're a system administrator, email marketer, or business owner, validating your DKIM signatures ensures your outbound emails are trusted by receiving mail servers and don't end up in spam folders.

What is a DKIM Checker Tool?

A DKIM checker is an online diagnostic tool that validates whether your domain has correctly implemented DKIM email authentication. DKIM works by adding a digital signature to your email headers, which receiving servers verify against a public key published in your DNS records. This verification process confirms that the email actually came from your domain and hasn't been tampered with during transmission. Our tool performs a complete DKIM record lookup, checking for proper syntax, key strength, and DNS configuration issues that could compromise your email security.

How DKIM Authentication Works

When you send an email, your mail server signs it with a private cryptographic key. The receiving server then looks up your public key in your domain's DNS records to verify the signature matches. This process creates a chain of trust that proves email authenticity. If the signature validation fails or no DKIM record exists, receiving servers may flag your messages as potentially fraudulent or assign them a lower trust score, significantly impacting delivery rates.

Why Use a DKIM Record Checker?

Regular validation of your email authentication setup prevents costly deliverability problems before they impact your business. Here's why checking your DKIM configuration matters:

• Prevent spoofing attacks: Verify that your domain is protected against impersonation and phishing attempts
• Improve inbox placement: Properly configured DKIM significantly increases the likelihood your emails reach the inbox rather than spam
• Maintain sender reputation: Email providers like Gmail and Outlook prioritize authenticated messages from domains with valid signatures
• Troubleshoot delivery issues: Identify configuration errors causing bounce rates or delivery failures
• Compliance requirements: Many industries require proper email authentication for regulatory compliance
• Monitor DNS changes: Catch accidental modifications to your DNS records that break authentication

Common DKIM Configuration Problems

Even experienced administrators encounter issues when implementing email authentication. Our DKIM lookup tool identifies these frequent problems:

Missing or incorrect selector records often cause validation failures. Each email service provider uses specific selectors (like "default._domainkey" or "google._domainkey"), and the corresponding TXT record must exist in your DNS. Syntax errors in the public key, incorrect key lengths, or expired keys also trigger authentication failures. Additionally, DNS propagation delays mean changes to your DKIM records may take hours to become visible globally, which our checker helps you verify across multiple DNS servers.

When to Check Your DKIM Records

Regular validation ensures continuous email deliverability. Run a DKIM verification in these scenarios:

• After initial email server setup or migration to a new provider
• When experiencing sudden drops in email delivery rates
• Before launching major email marketing campaigns
• After making any DNS or mail server configuration changes
• As part of monthly security and infrastructure audits
• When switching email service providers or adding new sending domains

Maximizing Email Deliverability

DKIM authentication works best as part of a comprehensive email security strategy. Combine it with SPF (Sender Policy Framework) records that specify authorized sending servers and DMARC (Domain-based Message Authentication) policies that tell receiving servers how to handle authentication failures. This triple-layer approach provides maximum protection against domain spoofing while ensuring legitimate emails consistently reach recipient inboxes.

Use our free DKIM checker to validate your email authentication setup in seconds. Simply enter your domain and selector to receive a detailed analysis of your DKIM configuration, including the public key value, record syntax validation, and recommendations for improving your email security posture. Regular verification helps maintain optimal deliverability and protects your domain reputation from malicious actors.