What are SPF, DKIM, and DMARC, and when are they needed?
Summary
What email marketers say9Marketer opinions
Marketer from Email Geeks explains DMARC is the only authentication method that explicitly ties "me" to the visible from-address seen by end users, emphasizing the importance of aligning SPF and DKIM with the visible address.
Email marketer from Reddit shares that DKIM is needed because it adds a digital signature to your emails, proving that the email truly came from your domain and hasn't been altered in transit. This helps build trust with email providers and improves deliverability.
Email marketer from Cloudflare explains that SPF, DKIM, and DMARC are essential because they provide a comprehensive framework for email authentication, improving deliverability, protecting your brand's reputation, and preventing email-based cyberattacks.
Marketer from Email Geeks explains that SPF is for defining which IPs are allowed to send mail, DKIM is for signing messages to verify authorization, and DMARC specifies what to do with messages that fail SPF and DKIM authentication.
Email marketer from Proofpoint shares that Implementing DMARC is important to protect your customers, partners, and employees from phishing attacks that spoof your domain name.
Email marketer from Sendinblue explains that SPF, DKIM, and DMARC are needed as soon as you start sending emails from your own domain, especially for marketing or transactional emails. They're essential for avoiding the spam folder and maintaining a positive sender reputation.
Email marketer from Mailjet shares that SPF, DKIM, and DMARC are needed to improve email deliverability and protect your domain's reputation by preventing spoofing and phishing attacks. Implementing these protocols builds trust with email providers.
Email marketer from Email Marketing Forum explains that DMARC is needed to specify what recipient mail servers should do with emails that fail SPF and DKIM checks. This helps prevent phishing attacks by instructing servers to reject or quarantine unauthenticated emails.
Email marketer from SparkPost shares that SPF should be implemented to specify which mail servers are authorized to send emails on behalf of your domain, preventing unauthorized senders from using your domain to send spam or phishing emails. This ensures email is correctly identified.
What the experts say3Expert opinions
Expert from Word to the Wise explains that DMARC is a domain authentication protocol that helps protect email senders and recipients from spam, phishing, and spoofing.
Expert from SpamResource.com explains that SPF, DKIM, and DMARC are mechanisms to verify the authenticity of email messages and provides a breakdown for each record and their purpose.
Expert from Email Geeks shares that DMARC can be expensive to set up correctly and might cause wanted mail to be blocked and suggests evaluating its necessity, especially if considering BIMI.
What the documentation says6Technical articles
Documentation from EasyDMARC explains that DMARC offers a reporting mechanism which allows domain owners to receive reports about email authentication results, providing insights into potential spoofing attempts and helping refine their email authentication policies.
Documentation from Google explains that SPF (Sender Policy Framework) is a DNS record that lists the mail servers authorized to send email from your domain. It helps prevent spammers from forging the 'From' address on your emails.
Documentation from AuthSMTP explains that SPF records use a specific syntax to define authorized sending sources, including IP addresses, domain names, and mechanisms like 'include:' to reference other SPF records. Understanding this syntax is crucial for proper SPF configuration.
Documentation from DMARC.org explains that DKIM (DomainKeys Identified Mail) adds a digital signature to outgoing email, allowing recipient servers to verify the message's authenticity and that it hasn't been tampered with during transit.
Documentation from Microsoft explains that DMARC (Domain-based Message Authentication, Reporting & Conformance) builds on SPF and DKIM to provide instructions to recipient mail servers on how to handle emails that fail authentication checks. It also provides reporting mechanisms.
Documentation from Port25 explains that DKIM key size is an important aspect of DKIM configuration, larger key sizes generally provide stronger security, but it's important to balance security with compatibility as some older systems may not support the largest key sizes.