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Protect Your Email Communications: Learn Why You Need the Security of DKIM!

Published on May 8, 2024

Discover how DKIM, alongside SPF, adds a robust layer of trust by verifying email senders and ensuring message integrity. Learn why your organization needs this powerful security tool, how it works, and what steps to take to implement it.

Learn How DKIM Complements SPF to Secure Your Email Communications

3 Musketeers2

It’s time to continue our journey into email security. In this series of blog articles we are examining the Three Musketeers who should be protecting your email correspondence – SPF, DKIM, and DMARC. These distinct and powerful security tools are an amazing team and each one works in a different but complimentary way to keep you safe and ensure your mail gets to its destination. If you missed the first blog in the series all about SPF (Sender Policy Framework) you can click here.

So, sharpen your rapier as we look at our second Musketeer – DKIM. It augments the security of SPF in two ways: 

  1. DKIM offers a way to verify a sender BEFORE delivering an email to the recipient inbox.
  2. DKIM's integrity as a verification method survives even when an email is forwarded. 

Let’s get to the details!

What is DKIM?

DomainKeys Identified Mail (DKIM) is an email authentication method. When an email server receives a message, it uses DKIM to confirm if the email is really coming from the domain it claims to be. This is achieved through a digital 'signature' generated from a cryptographic hash (digital fingerprint) of the email contents, which is then placed in the email's header. The signature is unique to your domain and proves the authenticity and integrity of the message. How does it work?

DKIM for Email Security – A Sign of Integrity:Wax Seal

The whole system relies on two keys: the private key and the public key. The private key is securely possessed by the sender and remains secret. It is used to create the ‘signature’ for the email. This key could be compared to a signet ring worn by a king. Such rings were unique to each king and were used to make an impression on a wax seal to close an envelope or scroll. Its unique markings would provide evidence that a message was authentic and originated with that king. It also would be obvious if the seal had been broken or tampered with in transit, making the contents questionable. The signature in the email header is like that wax seal, carrying the unique markings of the sender’s domain.

The public key, which is not kept secret, is stored in the DNS records of the sender’s domain. When an email arrives at the recipient’s email server, it looks up that public key. This key verifies the signature in the email header, indicating the email has not been altered and originated from the claimed sender. So, the recipient’s email server is like a king’s steward or clerk. He looks at the wax seal on a letter or scroll and verifies it as genuine and intact by comparing it to a public record of the signet ring’s imprint (the public key). Once confirmed, the steward could deliver the message to the recipient king.

Dkim Graphic

Why Your Organization Needs DKIM

Here are four important reasons you should set up DKIM:

  1. Authentication of Email Source: Once properly configured, DKIM confirms that your email originates from your specified domain and that its contents have not been altered in transit.
  2. Enhanced Email Deliverability: Emails authenticated via DKIM are less likely to be rejected or marked as spam by ISPs. This improves deliverability and ensures that your communications reach the intended recipients.
  3. Protection Against Email Spoofing, Phishing, and Scams: By verifying that the messages are genuinely from the indicated sender, DKIM reduces the risk of receiving spoofed emails, thereby protecting your organization from phishing attacks and scams.
  4. Improved Reputation and Trust: Using DKIM increases your email’s credibility, enhancing your organization's overall email reputation. Many mail service providers like Microsoft and Google see DKIM as a favorable sign that your mail is legitimate. This results in a higher rate of delivery to inboxes from those providers.

Implementing DKIM in Your Organization

Setting up DKIM involves generating the two cryptographic keys (one private and one public) and configuring your email server to attach a DKIM signature to all outgoing emails. The public key is then published in your DNS records openly accessible to verify the signature of your emails. Our team at allCare IT is ready to help you set up the email security for your domain. Contact us for more information.  

Beyond DKIM: Looking Ahead to DMARC

We have explored how DKIM significantly enhances email security when used alongside SPF. It is a significant augmentation because it improves your mail deliverability and survives when an email is forwarded. It gives added protection against your message contents being altered in transit. However, your comprehensive strategy for email security is incomplete without the third Musketeer – DMARC! Stay tuned for the next post in this series, where we will look at the nuts and bolts of DMARC, completing our overview of the Three Musketeers of email security.

Ready to Boost Your Email Security? Don’t let your email defenses lag behind. Contact allCare IT today to implement DKIM along with SPF and DMARC. Strengthen your email security framework and protect your vital flow of communication.