DKIM vs. DMARC – Security Boulevard


It is not wise to compare DMARC vs. DKIM. They are both authentication protocols used to validate emails, prevent identity theftand protect your email domain.

But that’s where the similarities end. Although both protocols use public key cryptography, each uses a different method to validate your mail flow. These security mechanisms are not intended to override each other.

Have you read our blog post :t DKIM versus SPF versus DMARC? If not, you might be wondering how these three email authentication standards work together.

In this article, we dive into DKIM vs. DMARC and why they are both necessary to protect your domain.

What is DKIM?

DKIM stands for Domain Key Identified Mail. This authentication method verifies the origin and validity of an email using public cryptography.

With DKIM, every email is signed with a digital ID DKIM-signing created using a private cryptographic key to reflect its authenticity.

The receiving server checks if the corresponding public key is listed in the sending domain. DKIM registration. If the key is valid, the receiving server authenticates the message as legitimate and unmodified before delivering it to the intended recipient.

When you configure DKIM and create a DKIM recordyou add a layer of benefits to protect your domain, such as those listed below:

  • Increase your brand trust and reputation.
  • Help your recipients identify and trust your emails. This, in turn, can increase your click-through rates, conversion rates, and sales.
  • Protect your domain from malicious senders trying to use your domain in spoofed emails.
  • Help receive servers to mark any scam emails as “bad” and possibly send complaints to your ISPs.
  • Fight spam since you’re a verified sender on all your emails (not just a third party pretending to be you). Spam filters are more likely to block spam impersonating your domain.

Can DKIM work without DMARC?

The short answer is yes. With DKIM, your mail server applies a digital signature to all outgoing messages, proving that your emails are from you. The receiving server verifies the digital signature using the corresponding public key in your DKIM record.

DKIM lets you digitally sign every email you send. This identifier will not be present on fraudulent emails. If a malicious sender spoofs your domain in a fake email, the receiving server will reject it (since it won’t have a valid DKIM signature).

What is DMARC?

DMARC stands for Domain-based message authentication, reporting and compliance. This is an authentication method that leverages SPF and DKIM to verify your messages and send reports detailing the behavior of your messages before the spam filters used by most ESPs.

While discussing DMARC vs. DKIM vs. SPF, you can’t put one on top of the other. Good DMARC compliance cannot be achieved without DKIM or SPF.

DKIM can work without SPF (and vice versa), but DMARC without DKIM or SPF is not recommended. Essentially, DMARC determines whether emails should be delivered to their recipients and how they should be handled.

A DMARC record contains detailed instructions telling receiving servers what to do with emails sent on behalf of your domain if they pass or fail SPF and DKIM checks.

DMARC authentication is based on three policies that should be configured gradually as you increase your mail flow. These policies are:

  • p=none: indicates that no action should be taken by the recipient; the email is delivered as usual. This is the basic configuration of DMARC, and it can send many messages directly to the inbox without verification.
  • p=quarantine: Blocks messages based on SPF and DKIM configuration. Any messages that fail authentication here are sent to spam folders.
  • p=reject: Designed to block messages that fail DMARC, SPF, and DKIM authentication.

When an email passes SPF authentication, the sender is allowed to send emails to the domain name according to the SPF record.

When an email passes DKIM authentication, it means that the email’s DKIM signature matches the public key in the domain’s DKIM record.

When an email passes DMARC authentication, it means SPF and/or DKIM checks passed and SPF and/or DKIM alignment passed.

Alignment means that the return path address (for SPF) and/or DKIM address (for DKIM) matches the From: address in an email.

This ensures that only emails that pass SPF and/or DKIM checks and DMARC verification reach the recipient’s inbox.

Can DMARC work without DKIM?

Technically, yes. A barebones DMARC setup can work without DKIM, although this is not recommended. DKIM minimizes false negatives authenticated by DMARC while providing an additional layer of security.

What is the difference between DKIM and DMARC?

DKIM and DMARC do very different things that complement each other in the closed echo chamber of a single domain. While it’s true that DKIM and DMARC rely on the use of cryptographic keys to authenticate legitimate senders, that’s where all the similarities end. Here are some of the main differences between DKIM vs. DMARC:

  • DMARC generates a report each time a message fails authentication.
  • DKIM uses digital signatures to verify legitimate senders.
  • DKIM is only an authentication method, while DMARC generates aggregated reports to help you fine-tune your email strategy.
  • DKIM allows receiving servers to verify the digital signature of all your emails.
  • With DMARC, you see when a receiving server verifies your domain and marks the message as legitimate on every report.

What does SPF add to email authentication?

FPS stands for Sender Policy Framework, an email authentication method. SPF works with DKIM and DMARC, adding a layer of security to your email authentication. With SPF, you can specify all sending sources (IP addresses or third-party providers) that are allowed to send mail on behalf of your domain. When an email is sent, the receiving server uses the SPF record to match it to the sending domain.

When bad actors exploit your domain, the receiving server fails SPF because the sender is not authorized. As such, the email is either sent to spam or rejected entirely.

By using SPF and DKIM together, you can help protect your domain from malicious senders.

SPF instantly blocks fraudulent emails and maintains your domain reputation. Of course, this system works best with a fully configured system DMARC Policy. By using SPF and DKIM together under DMARC, you can prevent malicious senders from using your domain.

Final Thoughts

Email authentication protocols have made significant progress in combating spam and malicious senders. But to protect your domain and your recipients, you will need to implement SPF vs. DKIM vs. DMARC.

If you’re starting with your email domain’s security framework, keep in mind that all three protocols are critical.

Ready to authenticate and secure your domain in no time? We at EasyDMARC are happy to help!

DKIM vs DMARC post appeared first on EasyDMARC.

*** This is an EasyDMARC Security Bloggers Network syndicated blog written by EasyDmarc. Read the original post at:


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