How to configure DomainKeys DKIM for email authentication and is it still relevant?

Summary

The consensus from the provided information indicates that DomainKeys is largely deprecated and no longer relevant for email authentication. The focus should be on DKIM (DomainKeys Identified Mail), which is the modern standard. DKIM configuration involves generating a public/private key pair, adding the public key to your DNS records as a TXT record, configuring your email sending server to sign outgoing emails with the private key, and then verifying the configuration. DKIM improves email deliverability by verifying the authenticity of emails, preventing spoofing and phishing attacks. DKIM should be used in conjunction with SPF and DMARC for a comprehensive email authentication strategy.

Key findings

  • DomainKeys is Deprecated: DomainKeys is considered outdated and is no longer widely used or supported.
  • DKIM is the Current Standard: DKIM is the recommended method for email authentication.
  • DKIM Improves Deliverability: Implementing DKIM helps improve email deliverability and sender reputation.
  • DKIM Prevents Spoofing: DKIM helps prevent email spoofing and phishing attacks by verifying email authenticity.
  • DKIM Configuration Steps: DKIM setup requires generating key pairs, adding the public key to DNS, and configuring the email server to sign messages.

Key considerations

  • Focus on DKIM Implementation: Direct resources towards DKIM configuration instead of DomainKeys.
  • DNS Record Management: Ensure correct DNS TXT records are created and maintained for DKIM.
  • Email Server Configuration: Properly configure the email server (MTA) to sign outgoing messages with the private key.
  • DKIM Testing and Verification: Use a DKIM record checker to verify and validate the DKIM setup.
  • SPF and DMARC Integration: Implement SPF and DMARC alongside DKIM for a robust email authentication strategy.

What email marketers say
14Marketer opinions

The provided answers indicate that while DomainKeys is an older email authentication method, it's largely deprecated and superseded by DKIM (DomainKeys Identified Mail). The focus should be on properly configuring DKIM for email authentication. DKIM involves generating a public/private key pair, adding the public key as a DNS TXT record, configuring the email server to sign outgoing messages with the private key, and using a DKIM record checker to verify the setup. Properly configured DKIM helps verify the authenticity of emails, preventing spoofing and improving deliverability and sender reputation.

Key opinions

  • DomainKeys Deprecated: DomainKeys is largely deprecated and no longer widely supported or validated.
  • DKIM is the standard: DKIM (DomainKeys Identified Mail) is the current standard for email authentication.
  • Improved deliverability: Properly configured DKIM helps improve email deliverability and sender reputation.
  • Verifies Email Authenticity: DKIM helps verify the authenticity of emails, preventing spoofing and phishing.

Key considerations

  • Focus on DKIM: Focus your efforts on DKIM implementation rather than DomainKeys.
  • DKIM Setup Steps: DKIM setup involves generating a public/private key pair, publishing the public key in DNS, and configuring your email server.
  • Key Rotation: Consider best practices for key rotation to maintain security.
  • DKIM Validation: Use a DKIM record checker to verify proper configuration.
Marketer view

Email marketer from Email Marketing Forum shares that while DomainKeys was a precursor to DKIM, it's now deprecated, and focusing on DKIM and SPF is sufficient.

July 2021 - Email Marketing Forum
Marketer view

Marketer from Email Geeks suggests creating a virtual testbed environment with legacy CentOS builds, BIND, and sendmail to test DomainKeys, as modern software doesn't support it.

October 2023 - Email Geeks
Marketer view

Email marketer from Reddit says DomainKeys is outdated and has been superseded by DKIM. Focusing on DKIM implementation is the best approach for modern email authentication.

September 2023 - Reddit
Marketer view

Email marketer from GlockApps says to verify DKIM is to use a DKIM record checker to inspect your DNS settings and ensure your email server is correctly signing messages.

September 2022 - GlockApps
Marketer view

Email marketer from Mailchimp shares that DKIM helps verify the authenticity of emails sent from your domain, improving deliverability. They detail the steps of adding a DKIM record to your domain's DNS settings, emphasizing its role in building trust with email providers.

May 2022 - Mailchimp
Marketer view

Email marketer from SendGrid answers that DKIM helps prevent email spoofing and phishing attacks by allowing recipients to verify that an email was indeed sent by the domain it claims to be from. Properly configured DKIM improves email deliverability and sender reputation.

April 2022 - SendGrid
Marketer view

Marketer from Email Geeks explains testing with testing mode before full use and asks about the specific software being used to sign messages with DomainKeys.

April 2023 - Email Geeks
Marketer view

Email marketer from AuthSMTP shares that DKIM is used to assert that a message is genuine and hasn't been altered during transit. It is not a guarantee of deliverability but adds authentication.

May 2023 - AuthSMTP
Marketer view

Marketer from Email Geeks confirms that the provided DNS record format looks correct for DomainKeys, with t=y indicating testing mode.

March 2022 - Email Geeks
Marketer view

Marketer from Email Geeks explains that sender adoption of DomainKeys is irrelevant if no receiver is checking it, and most senders simply never turned it off in their MTA.

May 2023 - Email Geeks
Marketer view

Email marketer from EasyDMARC details the DKIM setup steps, including generating a public/private key pair, publishing the public key as a DNS TXT record, and configuring the email server to sign outgoing messages with the private key.

February 2023 - EasyDMARC
Marketer view

Email marketer from SparkPost explains how to set up DKIM by generating a key pair, adding the public key to DNS, and configuring the email infrastructure to sign outgoing messages with the private key. It also covers key rotation best practices.

April 2021 - SparkPost
Marketer view

Email marketer from Proofpoint answers that DKIM is generally preferred over DomainKeys because of its more advanced cryptographic methods and greater adoption across the email ecosystem.

October 2022 - Proofpoint
Marketer view

Marketer from Email Geeks clarifies that DomainKeys is deprecated and no longer in use, even by Yahoo!, the originator.

September 2023 - Email Geeks

What the experts say
4Expert opinions

The provided answers present a somewhat conflicting view. Some sources state DomainKeys is deprecated and irrelevant, adding unnecessary processing overhead with signatures often failing. Others suggest DKIM is the relevant standard for email authentication and should be used with SPF and DMARC to prevent spoofing. The consensus indicates a shift away from DomainKeys towards DKIM as the preferred method for email authentication.

Key opinions

  • DomainKeys Status: DomainKeys is largely superseded and not widely validated, making it less relevant.
  • DKIM as Authentication: DKIM (DomainKeys Identified Mail) is the modern standard for email authentication and spoofing prevention.
  • Integration with SPF/DMARC: DKIM should be implemented alongside SPF and DMARC for robust email authentication.

Key considerations

  • Focus on DKIM: Prioritize configuring DKIM over DomainKeys due to its widespread adoption and relevance.
  • Deprecation Awareness: Be aware of the deprecation status of DomainKeys and avoid spending resources on it.
  • Comprehensive Authentication: Implement a comprehensive email authentication strategy using DKIM, SPF, and DMARC.
Expert view

Expert from Email Geeks says many ESPs layered DKIM on top of existing DomainKeys implementations, but DomainKeys signatures were often failing due to lack of care.

October 2023 - Email Geeks
Expert view

Expert from Email Geeks says DomainKeys is extra processing time and bytes, and not used by recipients, so whatever you do doesn’t matter.

December 2022 - Email Geeks
Expert view

Expert from SpamResource.com explains that DKIM (DomainKeys Identified Mail) is an email authentication system designed to detect email spoofing by providing a mechanism to allow mail receivers to determine whether incoming email from a domain is authorized by that domain's administrators. It is still very relevant and should be used with SPF and DMARC.

November 2023 - SpamResource.com
Expert view

Expert from Word to the Wise explains that DomainKeys has been superseded by DKIM and is no longer relevant. Systems that support DKIM generally do not validate DomainKeys, making it unnecessary to configure. Focus efforts on DKIM implementation instead.

July 2024 - Word to the Wise

What the documentation says
4Technical articles

The documentation collectively outlines DKIM (DomainKeys Identified Mail) as a method for cryptographically signing email messages, allowing a signing domain to claim responsibility and a recipient to verify the signature. Configuration involves generating key pairs, adding the public key to DNS records (TXT record), configuring the mail server to sign emails with the private key, and testing the setup. OpenDKIM provides an open-source implementation. Microsoft details DKIM setup within Microsoft 365. The goal is to ensure email authenticity and prevent spoofing.

Key findings

  • DKIM Purpose: DKIM provides a cryptographic method to sign email messages and verify the sender's authenticity.
  • Configuration Steps: Configuration involves key generation, DNS record addition (TXT), and mail server configuration.
  • Open Source Implementation: OpenDKIM provides an open-source DKIM implementation option.
  • Verification is Key: Testing is essential to ensure proper DKIM configuration and implementation.

Key considerations

  • Key Management: Properly generate and manage DKIM key pairs.
  • DNS Configuration: Ensure accurate DNS TXT record creation for the DKIM public key.
  • Mail Server Integration: Correctly configure the mail server (e.g., Sendmail, Postfix, Microsoft 365) to sign outgoing emails.
  • Testing and Validation: Thoroughly test the DKIM setup to validate its correct function.
Technical article

Documentation from OpenDKIM.org details how to configure OpenDKIM, an open-source DKIM implementation, including generating keys, configuring the signing table, and integrating with mail transfer agents (MTAs) like Sendmail or Postfix.

May 2023 - OpenDKIM.org
Technical article

Documentation from Valimail explains DKIM setup involving generating a DKIM key pair, adding the public key to your DNS records as a TXT record, and configuring your email sending server to sign outgoing emails with the private key. It also emphasizes the importance of testing the DKIM configuration to ensure proper implementation.

June 2021 - Valimail
Technical article

Documentation from ietf.org details the DomainKeys Identified Mail (DKIM) Signatures specification, explaining how it provides a method for cryptographically signing email messages, permitting a signing domain to claim responsibility for a message and a recipient to verify the signature.

October 2021 - ietf.org
Technical article

Documentation from Microsoft explains how to use DKIM to sign email sent from your Microsoft 365 custom domain. Signing outbound email messages with DKIM allows receiving email systems to verify that messages sent from your organization's domain are authentic.

April 2024 - Microsoft