You might have heard a lot about email authentication and how implementing protocols like SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) can help you strengthen your defenses against cybersecurity threats. In the ongoing battle against email-based threats like phishing, spoofing, and spam, these three protocols are your best allies. They serve as a strong layer of defense against email-based threats, ensuring the integrity, authenticity, and security of your communications, which is why major email service providers have mandated the deployment of these protocols as a part of a robust cybersecurity strategy.
We are certainly witnessing a surge in the adoption of these authentication protocols, but there are still many organizations that are oblivious to the importance and benefits of implementing them. If you’re one of them, this is your sign to adopt these email authentication protocols before it’s too late.
To make things easier for you, this article will take you through what each protocol does and how they work together to protect your email communications.
What is Sender Policy Framework (SPF)?
When deploying an email security strategy, SPF, or Sender Policy Framework, is the first and foremost mechanism that defends your email ecosystem against phishing, spoofing, and malware attacks. This authentication protocol can help you ensure that the messages sent from your domain are actually from you and not an attacker pretending to be you. This is done by specifying which mail servers are allowed to send emails on behalf of your domain.
How Does SPF Work?
Here’s a breakdown of how SPF works to protect your organization from email spoofing and phishing attacks:
- For SPF to work, you need an SPF record, which is essentially a TXT record that includes a list of email servers that are permitted to send emails on behalf of your domain. Once your SPF record is up, it’s all set to start protecting your email communications.
- When you send an email from your domain, it travels from the sending mail server to the recipient’s mail server. Upon receiving the email, the recipient’s mail server performs a DNS lookup to retrieve the SPF record associated with your domain.
- The receiver’s server then examines the SPF record to see if the IP address of the sending server is listed as an authorized sender for that domain.
- If the IP address matches, the email passes the SPF check, which means it is considered legitimate by the mail server and delivered to the recipient’s inbox. If the sending server’s IP address does not match any of the authorized IP addresses, the SPF check fails, and the email is perceived as fraudulent.
Why Do You Need SPF?
SPF is not like any other email security measure as it specifically focuses on verifying the authenticity of the sender’s server, providing a first line of defense against email spoofing and phishing attacks. By ensuring that only authorized senders dispatch emails from your domain, SPF keeps malicious actors at bay and prevents them from impersonating your domain and sending fraudulent emails.
In the worst-case scenario, if an attacker manages to send fraudulent emails on your behalf, it would not only damage your organization’s reputation but could also lead to financial loss, legal repercussions, and a loss of trust from your customers. This is where SPF comes in to safeguard your email communications and maintain the integrity of your brand.
What is DomainKeys Identified Mail (DKIM)?
The second email authentication protocol that follows SPF is DomainKeys Identified Mail or DKIM. This mechanism allows you to sign your emails digitally to ensure that no one tampers with them while they are in transit to the recipient’s mailbox. To cross-check the authenticity of the email, the receiving server extracts the public key published in the DNS and tallies it with the digital signature.
How Does DKIM Work?
For DKIM to work, you have to start with two cryptographic keys— one is a private key, and the other is a public key. As you might have guessed, the private key is kept secure on the sender’s mail server, and the public key is published in the DNS. If you have these two keys configured, your DKIM is all set to ensure that your messages have not been messed with.
- The message sent from your mail server uses the private key to create a unique digital signature for the email. So, all the emails sent from your domain that include a DKIM header also carry this digital signature.
- As soon as the recipient’s server receives the mail, it looks for the public key in the DNS and verifies it with the private key in the mail. To do so, the server has to first decrypt the signature, and only then it can compare the private and the public keys.
- If the keys match, the email will be well-received by the mail server and might as well land in the inbox. If not, chances are the mail will be pushed into the spam folder or rejected altogether.
Why Do You Need DKIM?
It is safe to say that DKIM is a notch above SPF, especially when it comes to ensuring the integrity of your email content. With DKIM, it is not only about where the email is coming from but also if it is authenticated. The cryptographic keys ensure that the content has not been altered during transit. This means that your clients can trust that the emails they receive are exactly as you sent them and not something an attacker sent under the garb of your domain, which ultimately affects the credibility of your communications.
Not to mention, it also helps protect your organization’s reputation and improves email deliverability, ensuring that your messages reach their intended recipients without a hitch.
What is Domain-based Message Authentication, Reporting, and Conformance (DMARC)?
DMARC, the third layer of protection and perhaps the most effective mechanism out of the three, helps you with all-around protection of your email communications. It is built on the foundation laid by SPF and DKIM, which means it is not only capable of authenticating emails but also handling emails that fail authentication checks by allowing you to specify the policies that define how these emails should be treated.
How Does DMARC Work?
As you already know, SPF and DKIM are the foundation of DMARC. This means that for DMARC to work, you must have at least one of these email authentication protocols in place. If you have them aligned, you can go on to publish your DMARC policies.
- The first step of setting up DMARC is to configure DMARC policies. The policies you publish in DNS specify how to handle emails that fail SPF and/or DKIM checks. For example, it can instruct the receiving server to reject, quarantine, or take no action on such emails. Once you have decided upon the policy and published it on the DNS, the mail servers get to work.
- When you send an email, the recipient’s mail server first performs the usual SPF and DKIM checks to verify that the email is sent from an authorized server and has not been tampered with.
- If the email passes both SPF and DKIM checks and the domains are aligned, it is delivered to the recipient’s inbox. If it fails one or both checks, the recipient’s server refers to the DMARC policy to decide the next step– reject (bar from entering the mailbox), quarantine (send to the spam folder), or none (simply let it in).
Why Do You Need DMARC?
Undeniably, the most robust and comprehensive authentication mechanism, DMARC, provides critical protection against email spoofing and phishing attacks. With SPF and DKIM as the foundation, it not only authenticates your emails but also enforces policies for managing messages that fail these checks, which reduces the risk of fraudulent emails reaching your recipients.
Moreover, DMARC implementation also comes with a reporting feature that gives you insights into how your security strategies are performing and if there are potential security threats that you should be wary of.
Are you wondering if you need all of these protocols for well-rounded protection against malicious attacks? The simple answer is— yes.
Image sourced from rejoiner.com
With cybersecurity attacks becoming more severe and frequent than ever, it is clear that you need something more than a single-layered approach. When SPF, DKIM, and DMARC come together, they create a strong and effective defense system that addresses multiple aspects of email security. You can rely on this multi-faceted approach to protect your organization against spoofing and phishing attacks and enhance email deliverability. No wonder giants like Google, Yahoo, and Microsoft have made them a non-negotiable aspect of any email security strategy.
Get Started with SPF
Ready to start your organization’s email authentication journey? Take the first step towards email security by implementing SPF. Get in touch with us at AutoSPF to configure SPF quickly and accurately. You can trust our team of experts to handle everything from creating an SPF record to managing one.
