A DKIM record is a type of DNS record that enables email authentication by adding a cryptographic signature to outgoing emails. This signature allows receiving mail servers to verify that an email was sent from an authorized source by checking the domain's DKIM record and ensuring that its content has not been altered in transit. DKIM is an essential component of deliverability, working alongside SPF and DMARC to prevent email phishing and spoofing attacks, and unauthorized email use.
By implementing DKIM, you enhance your domain’s reputation, build trust with email providers, and improve your email deliverability. DKIM helps authenticate emails for a given domain, ensuring that only authorized messages are delivered. Without DKIM, your emails are more likely to be flagged as spam or rejected altogether, leading to lower open rates and reduced engagement. Proper DKIM authentication ensures that your messages reach your recipients’ inboxes while protecting your brand’s integrity.
The Free DKIM Checker Tool helps you verify and analyze your DKIM record to ensure it is properly configured for secure email authentication. To validate your records, use the DKIM checker tool by entering your domain and selector. The tool retrieves the DKIM record from your DNS settings using specific query methods to access DNS information. It also helps users locate and identify the DKIM signature within the email header, highlighting the importance of the 'DKIM-Signature' email header and its components, such as the s= tag, for verifying email authenticity. It then checks whether the record is present, correctly formatted, and valid.
The tool also detects common misconfigurations, such as missing or incorrect public keys, syntax errors, formatting errors, or expired DKIM records. By using the DKIM Checker, you can quickly identify and fix issues that may be affecting your email deliverability and security. Regularly checking your DKIM record ensures that your email authentication remains effective, protecting your domain from spoofing and phishing threats.
Yes, the DKIM Checker Tool is completely free to use. You can verify your DKIM records, detect configuration issues, and ensure your email authentication is correctly set up without any cost.
Generating a DKIM record involves creating a cryptographic key pair—one private key used by your mail server to sign emails and one public key added to your domain’s DNS records for verification. Our DKIM Generator tool automates this process in just a few simple steps:
Note: If your organization uses several email services or selectors, you may need to create and manage multiple keys. Each key is stored as a separate DNS record, allowing different authentication credentials for each sender or service within the same domain.
Once implemented, DKIM will authenticate your outgoing emails, ensuring they pass security checks and reach recipients’ inboxes securely. Managing private keys securely is crucial, as private keys are used to sign emails and verify their authenticity in the DKIM process. Most modern email providers, such as Google Workspace, support 2048-bit DKIM keys for enhanced security.
The key length of your DKIM key directly impacts the security of your email authentication. The two most common DKIM key lengths are 1024-bit and 2048-bit, each with its own advantages:
If your DNS provider supports a 2048-bit key length, it is best to use it to future-proof your security. However, if compatibility issues arise, a 1024-bit key length can still provide a reasonable level of protection.
Misconfigurations in DKIM records can lead to authentication failures, especially if signatures are invalid or missing, affecting your email deliverability and security. Here are some of the most common DKIM errors:
To avoid these errors, always verify your DKIM record after setup using a DKIM Checker tool. Regular monitoring and periodic updates ensure your authentication remains effective and secure.
DKIM (DomainKeys Identified Mail) improves deliverability by authenticating your emails and building trust with email providers. When an email is sent, DKIM adds a special signature to the message header. This signature is verified by the recipient’s mail server using the public key published in your domain’s DNS. If the DKIM check passes, it confirms that the email was not tampered with and came from an authorized sender.
Email providers like Gmail, Outlook, and Yahoo prioritize authenticated emails when deciding whether to deliver them to the inbox or spam folder. A valid DKIM record helps prove that your emails are legitimate, reducing the risk of being marked as spam. Additionally, when DKIM is combined with SPF and DMARC, it strengthens your domain’s overall security and reputation. This results in higher inbox placement rates, increased open rates, and better engagement with your emails.
By using DKIM, you can ensure your messages are trusted by email providers, improve your sender reputation, and maximize your chances of reaching your recipients’ inboxes rather than being flagged as spam or rejected outright.
DKIM, SPF, and DMARC are three essential email authentication protocols that work together to improve deliverability.
Together, these protocols work to prevent spoofing, phishing, and spam, ensuring emails from your domain are properly authenticated and reducing the likelihood of your messages being flagged as suspicious or fraudulent.
A DKIM selector is a unique identifier that is used to locate and retrieve the correct DKIM public key from a domain’s DNS records. When a sender configures DKIM, they specify a selector that is used in the DKIM-Signature header of outgoing emails. The recipient’s mail server then uses this selector to look up the corresponding DKIM record in DNS and verify the email’s authenticity.
Selectors matter because they allow multiple DKIM keys to exist under the same domain without conflicts. This is especially useful when a domain uses multiple email services (e.g., a marketing platform, a CRM, and a transactional email provider), each requiring its own DKIM key. By assigning different selectors to each service, organizations can manage DKIM keys independently and rotate them when needed without affecting other services.
For example, if an organization uses “marketing” as a selector for an email marketing tool and “sales” for a CRM, the respective DKIM records in DNS would look like:
When choosing a DKIM selector, best practices include keeping it simple, descriptive, and unique for each email service. Properly managing DKIM selectors ensures seamless authentication and enhances overall email security.


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