Fact Sheet: Understanding DMARC, SPF, and DKIM for Business Email Security

With escalating cyber threats such as spam, phishing, and malware, ensuring the safety of email communications has become critical for businesses.

The upcoming requirements from Google and Yahoo for email authentication underscore the need for robust security protocols. This fact sheet explores DMARC, SPF, and DKIM—the triad that forms the cornerstone of email security.

Why is email authentication important for my business?

Email authentication is crucial for protecting your business from cyber threats like phishing and spoofing. It helps ensure that your emails are reliably delivered to your recipients' inboxes and not marked as spam. This is vital for maintaining your brand's reputation, securing your email communications, and ensuring important messages, such as contact requests from your website, are received.

Will the update affect me even if my business is not with Gmail or Yahoo?

Yes, the update will still affect your business even if you do not use Gmail for your email services. The requirement for updated DMARC records is not exclusive to emails sent to or from Gmail addresses. Many email service providers, including Yahoo and others, are adopting similar standards for email authentication. This means that regardless of the email service your business uses, having a properly configured DMARC record is crucial for ensuring that your emails are delivered successfully across all platforms.

Moreover, the principles behind DMARC, SPF, and DKIM are part of a global effort to improve email security and integrity. Email providers worldwide are increasingly relying on these standards to filter spam and phishing attempts, which means that emails failing to meet these authentication checks are more likely to be rejected or marked as spam, regardless of the recipient's email service.

What is DMARC?

DMARC stands for Domain-based Message Authentication, Reporting, and Conformance.

It is an email authentication, policy, and reporting protocol that enables email domain owners to protect their domain from unauthorised use, a practice commonly referred to as email spoofing.

DMARC allows domain owners to instruct email receivers on how to handle unauthenticated emails originating from their domain—options include rejecting the email outright or marking it as spam. It’s important to note that your DNS will not have a DMARC record by default, it needs to be added/updated.

Understanding DMARC Records and Policies

A DMARC record is published in the domain's DNS records. It outlines the policy that an email receiver should follow when dealing with emails that fail DMARC authentication checks. The record includes specifications for handling such emails, reporting mechanisms, and the address to which the reports should be sent.

DMARC policies are essentially the instructions included in the DMARC record that tell receiving mail servers how to enforce email authentication results. Policies can vary from:

None (p=none): The domain is monitored, but no action is taken on non-aligned emails. This policy is typically used for collecting data and understanding the domain's email flow without affecting delivery.

Quarantine (p=quarantine): Emails that fail DMARC checks are moved to the spam folder or otherwise quarantined.

Reject (p=reject): The strictest policy, where emails failing DMARC authentication are outright rejected and not delivered to the recipient.

What happens if I don't implement DMARC?

Failing to implement DMARC can leave your domain vulnerable to abuse in phishing or spoofing attacks, potentially damaging your reputation and eroding trust with your customers. Additionally, with email providers like Gmail and Yahoo moving towards stricter email authentication requirements, not having DMARC may lead to increased email rejection or filtering into spam folders, impacting your communication with customers and prospects.

Understanding SPF

SPF stands for Sender Policy Framework.

It is an email authentication method designed to prevent spam by detecting email spoofing, allowing domain owners to specify which mail servers are authorised to send email on behalf of their domain.

Email recipients can verify the SPF record in the DNS to confirm that the email comes from an authorised server.

The Role of DKIM

DKIM stands for DomainKeys Identified Mail.

It allows an outgoing mail server to add a digital signature to the headers of an email message. This signature can then be validated against a public cryptographic key published in the domain's DNS.

DKIM ensures the content of the email remains unaltered during its journey, providing an integrity check from the sender to the receiver.

Why Are These Protocols Important?

Collectively, DMARC, SPF, and DKIM authenticate the origin and integrity of emails, significantly mitigating the risk of email-based threats.

They aid in improving email deliverability by ensuring emails are not wrongly marked as spam or rejected by mail servers.

Implementing these protocols is key to safeguarding your brand’s reputation by preventing malicious email spoofing and phishing.

How do DMARC, SPF, and DKIM work together?

DMARC, SPF, and DKIM are complementary email authentication methods that provide a layered security approach. SPF allows senders to define which IP addresses are allowed to send email on behalf of a domain.

DKIM adds an encrypted signature to outgoing emails, verifying that the content has not been altered. DMARC ties these together with a policy that specifies how receiving mail servers should handle emails that fail SPF or DKIM checks, including reporting mechanisms for better visibility and control over email authentication.

Will implementing DMARC affect my email deliverability?

Properly implementing DMARC, along with SPF and DKIM, can positively affect your email deliverability by reducing the chance of your emails being marked as spam or rejected. It assures email providers that your emails are legitimate, which can improve your reputation as a sender and increase the likelihood of your emails reaching the inbox.

Upcoming Requirements

From February 2024, Gmail will mandate all businesses to authenticate their email communications with an updated DMARC record, with Yahoo implementing similar mandates.

Non-compliance could lead to a higher rate of email rejection or spam classification, adversely affecting your customer communication and the ability to receive website contact requests.

How to Implement These Protocols:

Assess Your Email Security: Verify if your domain has DMARC, SPF, and DKIM records set up.
Implement or Update Records: If absent, establish or refresh these records in your DNS, following best practices for each protocol.
Monitor and Adjust: Use the reporting feature of DMARC to track your email performance and make necessary modifications.

Need Help?

Setting up DMARC, SPF, and DKIM can be intricate, but is crucial for your email security. If you need assistance or are unsure how to proceed, we can help. Contact us for expert support in securing your email communications and ensuring compliance with the latest standards.

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