Summary
DMARC is a crucial email authentication protocol that helps prevent spammers from using your domain. It works by allowing domain owners to specify how receiving mail servers should handle emails that fail authentication checks (SPF and DKIM). The common approach is to create a DMARC record in the DNS settings of the domain that specifies a policy: 'none' (monitor), 'quarantine' (mark as spam), or 'reject' (block). Monitoring DMARC reports is vital to identify both legitimate sending sources and unauthorized attempts to use your domain. Implementing a gradual approach, starting with monitoring ('p=none') and progressing towards stricter policies ('p=quarantine' then 'p=reject') is generally recommended to avoid blocking legitimate emails. It is crucial to ensure that SPF and DKIM are properly configured before implementing DMARC. DMARC ultimately protects brand reputation, improves email deliverability, and enhances overall email security by limiting spoofing and phishing attacks.
Key findings
- Domain Protection: DMARC protects your domain's reputation by controlling who can send emails using your domain and preventing malicious actors.
- Authentication Policies: DMARC allows you to define policies (none, quarantine, reject) for handling unauthenticated emails.
- Visibility & Security: Implementing DMARC improves visibility into email traffic, enables enforcement of anti-spoofing policies, and enhances email security.
- DMARC Setup: DMARC allows domain owners to specify how email receivers should handle unauthenticated email purporting to be from their domain.
- Brand Reputation: Without DMARC spammers can send email that appears to be coming from your domain, damaging your reputation, deliverability and customer trust.
Key considerations
- Reporting Tools: Use a reporting tool to ensure all sources are aligned and passing authentication checks before enforcing a 'reject' policy.
- Gradual Implementation: Implement DMARC gradually, beginning with a 'monitor' policy to understand legitimate email sources.
- DMARC Monitoring: Continuously monitor DMARC reports to optimize email authentication and promptly identify potential threats.
- SPF/DKIM Dependency: DMARC requires properly configured SPF and DKIM records; these protocols must be set up first.
- Uncontrolled Servers: You cannot prevent emails from being sent on your behalf from uncontrolled servers, but DMARC can prevent them from being received.
What email marketers say
15 marketer opinions
DMARC (Domain-based Message Authentication, Reporting, and Conformance) is a crucial email authentication protocol that helps prevent spammers from using your domain. By implementing DMARC, you can instruct recipient servers on how to handle emails that fail authentication checks (SPF and DKIM). This includes options to monitor, quarantine, or reject unauthenticated emails, effectively protecting your domain's reputation and improving email deliverability. Monitoring DMARC reports is essential for identifying legitimate sending sources and unauthorized attempts to use your domain. A gradual implementation, starting with monitoring ('p=none') and progressing to stricter policies ('p=quarantine' then 'p=reject'), is recommended to avoid blocking legitimate emails.
Key opinions
- DMARC Protection: DMARC protects your domain's reputation by giving you control over who can send emails using your domain.
- Policy Enforcement: DMARC allows you to specify policies for handling unauthenticated emails: monitor, quarantine, or reject.
- Visibility: DMARC provides visibility into who is sending emails on behalf of your domain, helping identify spoofing attempts.
- Email Security: Improves email security by enforcing policies that prevent spoofing and phishing attacks.
- Reduces Impersonation: Configured DMARC, SPF, and DKIM can significantly reduce the chance of spammers impersonating your domain.
- Authentication Protocol: Without DMARC spammers can send email that appears to be coming from your domain, damaging your reputation, deliverability and customer trust.
- Sender Reputation: DMARC improves sender reputation and deliverability, thus boosting trust with mailbox providers and recipients.
Key considerations
- Reporting Tool: Use a reporting tool to ensure all email sources are aligned and passing authentication before changing DMARC policy to 'reject'.
- SPF & DKIM: Implement SPF and DKIM correctly before setting up DMARC. If SPF and DKIM are not setup then DMARC will not work.
- Gradual Rollout: Implement DMARC gradually, starting with 'p=none' to monitor and identify legitimate senders before enforcing stricter policies.
- DMARC Reports: Continuously monitor and analyze DMARC reports to optimize email authentication and maintain a strong security posture.
- Reject Doesn't Stop Attempts: Setting p=reject won't stop spoofing attempts, but it will prevent unauthenticated emails from being delivered.
- Reputation Damages: Without DMARC your domain can be impersonated and this damages your reputation, deliverability and customer trust.
Marketer view
Email marketer from Email Geeks advises to use a reporting tool to ensure all sources are aligned and passing before changing the DMARC policy to 'reject'. He emphasizes the importance of aligning the return-path with the friendly from and DKIM signing with the correct key.
28 Feb 2022 - Email Geeks
Marketer view
Email marketer from Email Geeks explains that setting p=reject instructs mailbox providers to reject unauthenticated emails using your domain, but it doesn't stop spoofing attempts. He suggests that blocking the IP address of the spoofer is limited to inbound mail on controlled servers.
9 Jul 2022 - Email Geeks
What the experts say
2 expert opinions
DMARC is an email authentication method used to protect your brand's domain from being spoofed in email attacks. Implementing DMARC involves setting a policy, such as 'reject', which instructs recipient servers to refuse emails that fail authentication. You need to monitor the emails, start in monitoring mode, and then advance to stricter protocols. DMARC requires careful setup and monitoring to avoid blocking legitimate mail while effectively preventing spammers from using your domain.
Key opinions
- DMARC Protection: DMARC protects your brand from email spoofing and phishing attacks.
- Control over Authentication: It allows you to control how recipient servers handle unauthenticated email claiming to be from your domain.
- Reject Policy: Setting the DMARC policy to 'reject' instructs recipient servers to refuse emails failing authentication checks.
Key considerations
- Careful Setup: DMARC requires careful setup and monitoring to avoid blocking legitimate mail.
- Monitoring Mode: Start in monitoring mode before advancing to stricter protocols to understand your email traffic.
Expert view
Expert from Word to the Wise shares that implementing DMARC allows you to protect your brand from email spoofing and phishing attacks by controlling how recipient servers handle unauthenticated email claiming to be from your domain. The expert also says that you need to monitor the emails, start in monitoring mode, and then advance to stricter protocols.
27 Feb 2022 - Word to the Wise
Expert view
Expert from Spam Resource explains that you can set the DMARC policy to 'reject', instructing recipient servers to refuse any email that fails authentication checks. This prevents spammers from successfully spoofing your domain, but requires careful setup and monitoring to avoid blocking legitimate mail.
23 Jan 2025 - Spam Resource
What the documentation says
5 technical articles
DMARC (Domain-based Message Authentication, Reporting, and Conformance) empowers domain owners to instruct receiving mail servers on how to handle messages that fail SPF and DKIM authentication checks. By creating a DMARC record in your DNS, you specify whether to reject or quarantine unauthenticated emails. Implementing DMARC effectively prevents spoofing and phishing attacks by clarifying how email receivers should handle these failures, significantly reducing the effectiveness of spoofing attacks. Before implementing DMARC, ensure SPF and DKIM are properly set up, as DMARC builds upon these protocols.
Key findings
- Domain Control: DMARC allows domain owners to specify how email receivers should handle unauthenticated email purporting to be from their domain.
- SPF/DKIM Dependent: DMARC builds upon SPF and DKIM; proper setup of these is crucial.
- Anti-Spoofing: DMARC prevents spoofing and phishing by allowing organizations to specify what happens to messages that fail SPF or DKIM checks.
- DNS Record: Creating and publishing a DMARC record to your domain's DNS records is the first step.
Key considerations
- Existing SPF/DKIM: Before implementing DMARC, ensure that SPF and DKIM are correctly configured for your domain.
- Reporting Importance: Monitoring DMARC reports is important to identify and address any legitimate sending sources that are not properly authenticating.
- Authentication Handling: DMARC tells receiving mail servers what to do with messages that fail authentication checks (SPF and DKIM), either reject them or mark them as spam.
Technical article
Documentation from RFC Editor (RFC7489) specifies that DMARC (Domain-based Message Authentication, Reporting, and Conformance) is designed to allow domain owners to indicate that their messages are protected by SPF and/or DKIM, and to give instructions if neither of those authentication mechanisms pass. DMARC defines how email receivers should handle failures, thus preventing spammers from using the domain.
29 Oct 2021 - RFC Editor
Technical article
Documentation from DMARC.org details how DMARC allows domain owners to specify how email receivers should handle unauthenticated email purporting to be from their domain. It clarifies that by publishing a DMARC policy, you can instruct receivers to quarantine or reject messages that fail authentication, significantly reducing the effectiveness of spoofing attacks.
25 May 2023 - DMARC.org
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