Mastering Email Security With DKIM, DMARC, and SPF

Mastering Email Security With DKIM, DMARC, and SPF

Oct 7, 2021, 8:44:36 AM Tech and Science

DKIM, SPF, and DMARC are all protocols that can be implemented for email authentication to ensure the security of email channels and improve email deliverability. 


DomainKeys Identified Mail is an email authentication protocol that ensures your emails remain secure in transit. DKIM uses digital signatures to check that the email was sent by a specific domain.

DKIM validates email communications in two steps. The first occurs on a server that sends DKIM-signed emails while the second occurs on a receiving server that checks DKIM signatures on incoming emails.

A pair of private and public keys enables these two DKIM steps. The private key is kept private and secure, either on the email server or with the ESP. The public key is added to the domain's DNS records and broadcasted to the world to aid message verification. This is accomplished by using a digital signature in all outgoing emails. The email can be considered authentic and secure when the receiving server checks that it is verified with a valid DKIM signature. 


Sender Policy Framework is another email authentication protocol like DKIM. SPF allows the owner of a domain to specify which email servers are permitted to send emails from that domain. 

While the email is being delivered, SPF identifies fake sender addresses. However, it is limited to detecting a falsified sender claim in the email's envelope, which is utilized when it bounces. When aligned with DMARC, SPF detects email spoofing, a common phishing scam that misuses the email address or domain name of a reputed company or trusted friend. 

SPF allows the recipient server to verify whether the email was sent from an IP address approved by the domain's administration during delivery. This is possible only when a list of permitted transmitting hosts and IP addresses are published in the DNS records for that domain. 


Domain-Based Message Authentication, Reporting, and Conformance is an email authentication standard or protocol that determines whether an email is authentic or not. It relies on SPF and DKIM to determine the authentication status of emails. It provides visibility of the sources sending emails from your domain, ensures better deliverability, and guarantees domain security so you don’t fall prey to spoofing, phishing, and impersonation attacks. 

Before we understand how to master these email security protocols, let’s take a look at why these protocols are becoming increasingly important.

In 2020, phishing attempts lead to loss of $1.9 billion. In recent years, massive data breaches and spoofing assaults have afflicted organizations all over the world. The information and funds that have been lost are gone forever. As a result, it's critical for businesses to establish strict email procedures in order to better secure their data and money. These procedures have a number of advantages. We’ve listed a few of them:

  • Using a DMARC record secures your image by preventing unauthenticated parties from sending emails using your domain.
  • SPF improves domain reputation and email deliverability while fighting domain impersonation and email spoofing to protect your brand reputation.

DKIM can help identify emails that aren’t spam and don't need to be filtered. This can be done if a receiving system maintains a whitelist of secure sending domains, a record of which can be kept locally or obtained from third-party certifiers. Receiving servers can then skip the filtering of signed emails from these white-listed domains and filter the remaining emails more aggressively. 

Why do we need to use DKIM, SPF, and DMARC together?

SPF and DKIM are combined in DMARC. The domain owner can use SPF to define which addresses are allowed to send emails on their behalf. DKIM employs an encrypted signature to confirm that an email sender is truly who they claim to be. Individual authentication identities are generated by both these systems, which may be used to verify and validate emails in a variety of ways. If you use these technologies, your receiving server can see who an email is from but won’t know if your traffic is properly configured. Therefore, it can't take any action based on that information.

DMARC, however, uses SPF and DKIM findings to properly determine whether an email is from an authorized sender or a fake imposter. It actively inhibits cyber assaults by enforcing a policy published by domain owners. That’s right! With DMARC, domain owners can advise receiving servers on how to handle emails, giving them complete control of their domain’s activities.

To implement DKIM, SPF, and DMARC protocols effectively, follow these simple steps:

  • Use email tracking on all your applications.

Email tracking will regulate and track gaps in the authentication. Ensure that all email apps are configured with DMARC, DKIM, and SPF. 

  • Use proper syntax and correct records for each domain. 

Wrong syntax leads to failure of email authentication. Keep the correct syntax in mind while implementing these protocols for your domain. 

  • Implement all three protocols in order for them to work in synergy. 

DMARC, SPF, and DKIM work best when used together. It is advised that you implement all these protocols for your domains to avoid being phished, spoofed, and spammed.

Published by nimisha rawat


Reply heres...

Login / Sign up for adding comments.