Everything you need to know about DMARC, SPF, DKIM Email Security
Email is an essential tool for businesses, used for everything from sales promotions and marketing campaigns to customer communication. Since email plays such a key role in connecting with customers and partners, it’s important to stay ahead of potential risks like email fraud and domain impersonation.
That’s where DMARC (Domain-based Message Authentication, Reporting, and Conformance) comes in. DMARC helps ensure the emails you send are legitimate, protecting your business from phishing and spoofing attacks. It works alongside SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) to verify that your emails are really coming from you.
In this blog, we’ll explain what DMARC is, how it works, and why it’s important for your business. We’ll also walk you through how to implement DMARC, how it works with SPF and DKIM, and how it helps keep your email communications secure. Let’s dive in and show you how to protect your business from email threats.
What is DMARC and Why is It Important?
DMARC (Domain-based Message Authentication, Reporting, and Conformance) is an email authentication protocol that helps protect your business from email fraud, phishing, and domain spoofing. Simply put, DMARC ensures that the emails you send are verified as coming from your domain and not from an imposter trying to deceive your clients or partners.
DMARC works alongside two other important email security protocols—SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail). SPF checks whether the server sending your email is authorised to send on behalf of your domain, while DKIM uses encryption to verify that the content of the email hasn’t been tampered with. When you implement DMARC, these two protocols work together to confirm that the email is legitimate. DMARC then adds an extra layer of protection by defining how to handle any email that fails these checks—whether to allow it, quarantine it, or reject it.
The primary purpose of DMARC is to safeguard your email communication by making it harder for cybercriminals to impersonate your domain. By setting up a DMARC record, you’re telling email receivers how to validate your emails and what to do if something doesn’t match. This makes it much less likely that your domain will be used for phishing scams or other malicious activities, helping protect your brand’s reputation and your customer’s trust.
How DMARC Works with SPF and DKIM
To understand how DMARC works, it’s important to first define the two protocols it works with: SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail).
SPF (Sender Policy Framework) is a security protocol that allows domain owners to specify which mail servers are authorised to send emails on behalf of their domain. Essentially, SPF helps email recipients verify that the email is coming from a trusted source, reducing the risk of phishing attacks and impersonation.
For example, let’s say you own the domain example.co.nz, and you use a third-party email marketing platform, such as Klaviyo, to send newsletters. You would set up an SPF record to authorise Klaviyo's mail servers to send emails on behalf of example.co.nz. If someone else tries to send an email pretending to be from example.co.nz but is using a different mail server, the recipient’s email system will check the SPF record and reject the email if the mail server isn’t authorised.
DKIM (DomainKeys Identified Mail), on the other hand, uses encryption to ensure that the contents of an email haven’t been tampered with while in transit. When an email is sent, DKIM adds a unique signature to the message, which recipients can verify by checking the signature against the public key listed in the domain's DNS (Domain Name System) records. This confirms the authenticity of the email and that it hasn’t been altered.
While SPF and DKIM each serve a distinct function, DMARC brings them together to provide more comprehensive email security. DMARC leverages both SPF and DKIM by checking if the email passes either or both of these protocols. If an email fails the checks, DMARC provides instructions on how to handle it—whether to allow, quarantine, or reject the email.
Can you have SPF without DMARC?
Yes, it’s possible to set up SPF without implementing DMARC, but it’s not enough on its own to fully protect your domain. SPF only checks if an email is sent from an authorised server but doesn’t specify how to handle a failed SPF check. DMARC fills in this gap by defining what should happen when an email doesn’t pass SPF or DKIM.
What’s the difference between DMARC and DKIM? While both DMARC and DKIM are email authentication protocols, DMARC is essentially a policy framework that ties together SPF and DKIM. DMARC provides instructions for what to do when an email fails either of these checks, while DKIM focuses on ensuring the integrity of the email content itself.
Together, SPF, DKIM, and DMARC form a robust email security system that helps prevent email fraud, domain spoofing, and phishing attacks, giving you better control over your email communication.
Benefits of Implementing DMARC:
Implementing DMARC (Domain-based Message Authentication, Reporting, and Conformance) can offer significant advantages for businesses, especially when it comes to protecting your brand, maintaining customer trust, and ensuring smooth email communication. Below are some key benefits of setting up DMARC for your email security:
1. Preventing Email Spoofing
Email spoofing is when cybercriminals send emails that appear to come from a legitimate source, often with the intent to trick recipients into revealing sensitive information. By implementing DMARC, you make it much harder for attackers to impersonate your domain. DMARC works in conjunction with SPF and DKIM to authenticate your emails and ensure they haven’t been tampered with or sent by an unauthorised source. This greatly reduces the risk of phishing attacks and domain impersonation, which can be costly to both your brand and your clients.
2. Enhancing Customer Trust
In an era of increasing cyber threats, customers and business partners are more aware of the risks of email fraud. If your business emails are consistently passing authentication checks, it builds credibility and reinforces the trust your customers place in your brand. When your emails are verified as legitimate, your recipients can feel confident that they are engaging with a trustworthy sender, leading to improved relationships and customer loyalty.
3. Ensuring Email Deliverability
DMARC can also improve the deliverability of your emails. Email providers, such as Gmail or Outlook, rely on DMARC checks to decide whether an email should land in the inbox or be flagged as spam. Without DMARC, your emails could be mistakenly marked as suspicious or blocked, affecting your marketing campaigns and communication efforts. By implementing DMARC, you’re helping to ensure that your emails are more likely to reach their intended recipients, increasing the effectiveness of your email marketing.
4. Gaining Insights through Reports
Another benefit of DMARC is the ability to access detailed reports on email authentication. DMARC’s reporting feature allows you to monitor who is sending emails on behalf of your domain, providing valuable insights into whether any unauthorised attempts are being made. This level of visibility helps you stay on top of potential threats and make adjustments as needed to enhance your email security.
How to Implement DMARC: Step-by-Step Guide
Implementing DMARC may sound complex, but with a clear and straightforward process, you can set it up effectively to secure your business’s email communication. Follow these simple steps to implement DMARC and protect your domain from email fraud and phishing attacks.
1. Assess Your Domain’s Current Email Setup
Before setting up DMARC, it’s essential to understand your current email setup, including how your emails are being sent and who is sending them. Take the time to review your existing email security protocols:
Check your SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) records. These two protocols are foundational for DMARC to work effectively. If you haven't set up SPF or DKIM yet, it's important to implement these first.
Identify all email-sending services. This includes internal systems, third-party email marketing platforms, customer support tools, and any other services that send emails on behalf of your domain. You need to ensure that these systems are included in your SPF record, and that they are properly configured with DKIM.
2. Generate and Publish a DMARC Record
Once your email setup is in place, the next step is to create a DMARC record. A DMARC record is a text entry in your domain’s DNS settings, specifying how email servers should handle emails that fail SPF and DKIM checks.
To generate your DMARC record, follow these steps:
Choose your DMARC policy. You’ll need to define your DMARC policy by deciding how to handle emails that fail authentication. Your options are:
None: This policy allows you to monitor your emails without rejecting any, perfect for a testing phase.
Quarantine: Suspicious emails that fail DMARC checks are sent to the spam or junk folder.
Reject: Emails that fail DMARC checks are outright rejected and not delivered.
Generate the DMARC record. A typical DMARC record will look something like this:
v=DMARC1; p=reject; rua=mailto:dmarc-reports@example.co.nz; ruf=mailto:dmarc-afrf@example.co.nz; pct=100
This record specifies:
v=DMARC1: The version of DMARC.
p=reject: The policy you’ve selected (reject in this case).
rua: The email address where aggregate reports are sent.
ruf: The email address for forensic reports.
pct=100: The percentage of emails that the policy applies to (100% in this example).
Publish your DMARC record. After generating your DMARC record, you’ll need to add it to your domain’s DNS settings. This step involves working with your DNS provider or using a DNS management tool to insert the record.
3. Monitor and Adjust Policies
Once your DMARC record is live, it’s important to monitor its performance and adjust the policy as needed. Here’s how:
Review DMARC reports. DMARC provides valuable reports that show you how your emails are performing. These reports can be used to identify legitimate sources sending emails on behalf of your domain, as well as any suspicious or unauthorised sources. Look for patterns, and take action if you notice any issues.
Adjust your policy over time. If you initially set your DMARC policy to “none” for monitoring purposes, you can gradually change it to “quarantine” or “reject” once you’re confident that all legitimate sources are properly authenticated. This gradual approach allows you to fine-tune your setup without disrupting your email communication.
Fine-tune SPF and DKIM records. Ensure that any new services or email-sending tools you adopt are properly included in your SPF and DKIM records. This ensures they can be authenticated and passed under your DMARC policy.
By following these steps, you’ll be able to implement DMARC successfully and provide an additional layer of protection for your business’s email communications.
Common Questions About DMARC
As you start to explore DMARC and its role in email security, you may have some questions about how it fits into your overall email protection strategy. Here are answers to some of the most frequently asked questions:
How is DMARC Different from SPF?
While both DMARC and SPF are email authentication protocols, they serve different functions:
SPF (Sender Policy Framework) checks if the email is coming from an authorised server for your domain. It verifies that the server sending the email is listed in your SPF record as an allowed sender.
DMARC, on the other hand, takes SPF a step further by adding an additional layer of protection. DMARC works by validating SPF and DKIM (another email security protocol) results. It then instructs email receivers on how to handle messages that fail authentication checks (e.g., reject, quarantine, or none).
In short, DMARC uses SPF (and DKIM) as its foundation but adds a policy and reporting function, making it more comprehensive in protecting your brand from phishing and spoofing attacks.
What is the Role of a DMARC Record?
A DMARC record is a set of rules that you place in your domain's DNS (Domain Name System) settings. It defines how email receivers should handle emails that fail DMARC authentication (based on SPF and DKIM checks). For example, it can instruct receivers to reject such emails, quarantine them, or simply monitor and report on them.
The DMARC record is essential because it ensures your email communication is protected, and it gives you control over how to handle any fraudulent or suspicious messages sent from your domain.
DMARC Best Practices for Businesses
To ensure your DMARC implementation is as effective as possible, follow these best practices:
Regularly Review and Update DNS Records
Your domain’s email security protocols, including DMARC, SPF, and DKIM, need to be regularly reviewed and updated. As your business grows or changes, so will the services and platforms that send emails on your behalf. This is why it’s important to keep your DNS records up to date, ensuring all legitimate email senders are included in your SPF and DKIM configurations.
Use Tools for Monitoring Email Authentication
There are many tools available to help monitor your DMARC and overall email authentication status. These tools can provide insights into how your emails are performing and whether they’re passing authentication checks. They also help you monitor for any unauthorised use of your domain, allowing you to take action quickly if needed. Regularly monitoring your DMARC reports will keep you ahead of any potential threats.
Educate Staff About Phishing Risks
Even with a strong DMARC policy in place, your employees are still a potential vulnerability point for email fraud. Educating your team about phishing attacks and the importance of email security is essential. Regular training sessions or awareness campaigns can help ensure your employees can recognise suspicious emails and act accordingly.
DMARC is a critical tool for businesses looking to protect their email communication, safeguard their brand reputation, and ensure their customers and partners are receiving legitimate emails. By implementing DMARC, you add an extra layer of security to your email infrastructure, making it harder for cybercriminals to spoof your domain and trick your audience.
Need Help with DMARC? Contact Email Studio
If you haven’t already, it’s time to take action. Start by reviewing your current email setup, generating and publishing a DMARC record, and monitoring its performance. Remember, email security is an ongoing process, and staying vigilant will help keep your business safe from email threats.
If you need help implementing DMARC or have any questions, our team at Email Studio is here to assist you. We specialise in setting up DMARC policies tailored to your business needs. Reach out today for support.
