Summary
Verifying the proper setup of DMARC, DKIM, and SPF is crucial for email deliverability. This process typically involves a two-pronged approach: checking your DNS records to ensure they are correctly published, and then sending test emails to analyze their authentication status in message headers. For continuous validation, particularly with DMARC, monitoring aggregate reports offers the most comprehensive insight into your email ecosystem and policy adherence.
Key findings
- Online DNS Record Tools: Utilize dedicated online lookup tools like MXToolbox, DMARC Analyzer, kitterman.com (for SPF), or EasyDMARC to verify the presence, validity, and correct syntax of your SPF, DKIM, and DMARC DNS TXT records. These tools provide an initial, quick validation of your DNS configuration.
- Email Header Analysis: Send a test email to an external address, such as a Gmail account, and then inspect the message's original headers. Look specifically for 'spf=pass', 'dkim=pass', and 'dmarc=pass' results to confirm successful authentication. Note that if SPF or DKIM fails, DMARC will also indicate a failure.
- Command-Line DNS Queries: For a manual check, use command-line tools like 'dig' or 'nslookup' to directly query the '_dmarc.yourdomain.com' TXT record to confirm its existence and published policy.
- DMARC Report Monitoring: The most comprehensive way to verify DMARC's effectiveness is by analyzing DMARC aggregate reports. These reports offer detailed insights into authentication results, policy application, and help pinpoint sources of unauthorized email, providing ongoing validation.
Key considerations
- Combined Verification Approach: For the most thorough verification, combine DNS record checks with post-send email header analysis to ensure both correct publication and active authentication.
- Tool Reliability: While many online tools are valuable, be aware that some services, like mail-tester.com, have been cited by experts for past inaccuracies, so consider cross-referencing results.
- SPF Specifics: When verifying SPF, watch out for common issues such as having multiple SPF records or exceeding the 10-DNS-lookup limit, which can prevent proper validation.
- Ongoing Monitoring: Beyond initial setup, DMARC aggregate reports are essential for continuous monitoring of email authentication status, confirming policy application, and identifying any unauthorized email sources.
What email marketers say
13 marketer opinions
To effectively verify your DMARC, DKIM, and SPF configurations, a blend of different testing methods is recommended. This includes leveraging online tools for a quick check of your published DNS records, sending test emails to observe authentication results in message headers, and for DMARC, actively reviewing aggregate reports for comprehensive, ongoing performance insights.
Key opinions
- DNS Record Checkers: A primary step involves using online platforms such as MXToolbox, DMARC Analyzer, EasyDMARC, kitterman.com, or DNSstuff to verify the presence, validity, and correct syntax of your SPF, DKIM, and DMARC TXT records in DNS.
- Header Analysis for Authentication: Sending a test email to an external address and then examining its message headers is crucial. Look for 'spf=pass', 'dkim=pass', and 'dmarc=pass' to confirm that authentication is actively working after the email is sent.
- DMARC Report Insights: For comprehensive DMARC verification, consistently monitoring DMARC aggregate reports offers deep insights into real-world authentication outcomes, policy application, and helps identify sources of unauthorized email.
- Direct DNS Queries: For a manual confirmation of your DMARC policy, performing a direct command-line `dig` request for the `_dmarc.yourdomain.com` TXT record can verify its existence and content.
Key considerations
- Multi-Method Approach: For the most robust verification, combine checks of your DNS records using online tools with post-send email header analysis and continuous DMARC report monitoring.
- Tool Reliability Varies: While many online verification tools are valuable, some, like mail-tester.com, have been cited for past inaccuracies, so consider cross-referencing results or using highly reputable services.
- Interdependence of Protocols: Be aware that DMARC authentication is reliant on SPF and DKIM. If either SPF or DKIM fails, DMARC will also indicate a failure, highlighting the need to ensure all three are correctly configured.
- Continuous Monitoring is Key: Beyond initial setup, DMARC aggregate reports are essential for ongoing oversight of your email authentication status, confirming policy application, and quickly identifying any unauthorized sending sources.
Marketer view
Email marketer from Email Geeks explains that the dmarcian checker is generally accurate for DMARC, and suggests performing a manual dig request for the _dmarc TXT record to check DMARC policy.
2 Sep 2022 - Email Geeks
Marketer view
Email marketer from Email Geeks shares that checking email headers can confirm DKIM, SPF, and DMARC status, noting that if SPF or DKIM fail, DMARC will also fail. He also expresses distrust in mail-tester.com due to past inaccuracies.
8 Mar 2025 - Email Geeks
What the experts say
5 expert opinions
Ensuring your DMARC, DKIM, and SPF configurations are functioning correctly requires a comprehensive approach, combining initial DNS record verification with post-send email header analysis and the continuous review of DMARC reports. These methods collectively provide robust validation, from confirming proper setup to monitoring ongoing authentication performance and identifying potential issues.
Key opinions
- Online Verification Tools: Leverage online tools like MXToolbox, DMARCian.com, DMARC.org's checker, DKIMValidator.com, and SPFRecord.com to quickly verify the correct publication and syntax of your DMARC, DKIM, and SPF DNS records.
- Email Header Analysis: Send a test email to a service like Gmail and then inspect the 'original message' headers for 'spf=pass', 'dkim=pass', and 'dmarc=pass' to confirm that authentication is successfully applied during mail flow.
- DMARC Report Insights: DMARC aggregate and forensic reports are critical for comprehensive verification, providing detailed insights into authentication results, policy application, and alignment across your entire email ecosystem.
- Command-Line DNS Checks: Utilize command-line tools like 'dig' to directly query your domain's DNS records, offering a granular method to confirm the existence and content of your DMARC, DKIM, and SPF entries.
- Google Admin Toolbox: The Google Admin Toolbox provides a convenient suite of tools for verifying various email-related DNS records, including those for DMARC, DKIM, and SPF.
Key considerations
- Holistic Verification: For the most reliable verification, combine DNS record checks with post-send email header analysis and continuous DMARC report monitoring to cover all aspects of your authentication setup.
- SPF Specific Issues: When verifying SPF, be mindful of common pitfalls such as having multiple SPF records or exceeding the 10-DNS-lookup limit, which can prevent proper validation and cause deliverability issues.
- Ongoing DMARC Monitoring: Beyond the initial setup, DMARC aggregate and forensic reports are indispensable for continuous oversight of email authentication, confirming policy enforcement, and quickly identifying any unauthorized email sources.
- Interdependency of Protocols: Remember that DMARC relies on the successful authentication of SPF and DKIM. If either of these underlying protocols fails, DMARC will also fail, underscoring the importance of correctly configuring all three.
Expert view
Expert from Stack Overflow, John Garden, shares methods to check if DKIM, SPF, and DMARC are working. He suggests sending an email to a Gmail address and then using "Show original" to inspect the headers. Look for 'spf=pass', 'dkim=pass', and 'dmarc=pass' to confirm successful authentication. He also mentions using 'dig' for DNS record verification.
2 Nov 2022 - Stack Overflow
Expert view
Expert from Spam Resource explains that DMARC setup can be verified using online tools such as DMARCian.com, DMARC.org's checker, MXToolbox, and Google Admin Toolbox. Additionally, DMARC reports provide authentication results that can confirm correct implementation.
22 Oct 2024 - Spam Resource
What the documentation says
3 technical articles
Effectively verifying your DMARC, DKIM, and SPF configurations involves inspecting email message headers for pass/fail results, alongside querying your domain's DNS records. Key email providers like Google and Microsoft offer specific guidance on these checks. Furthermore, ongoing analysis of DMARC aggregate reports provides a continuous view of your email authentication performance.
Key findings
- Email Header Validation: All major providers, including Google Workspace and Microsoft, advise checking email message headers for explicit 'spf=pass', 'dkim=pass', and 'dmarc=pass' results to confirm successful authentication after an email has been sent. For SPF, verifying the IP address matches your sending server is also critical.
- DNS Record Querying: Utilize online DMARC lookup tools, as well as command-line utilities like 'dig' or 'nslookup', to directly query your domain's TXT records. This confirms the presence, syntax, and published policy for SPF, DKIM, and DMARC in your DNS.
- DMARC Report Review: For ongoing, comprehensive verification, regularly monitor DMARC aggregate reports. These reports offer detailed insights into authentication outcomes, policy application, and help identify any unauthorized email sources.
- Platform-Specific Guidance: Consult official documentation from providers like Google Workspace Admin Help and Microsoft Learn, as they offer detailed, platform-specific steps and considerations for verifying SPF, DKIM, and DMARC within their respective environments.
Key considerations
- Holistic Verification Approach: For the most reliable verification, combine DNS record checks with post-send email header analysis to ensure both correct configuration and active authentication in real-world mail flow.
- Leverage Official Resources: Always refer to the latest guidelines from authoritative sources such as Google, Microsoft, and DMARC.org for accurate and up-to-date verification methods specific to your email environment.
- Continuous Monitoring is Essential: Beyond initial setup, DMARC aggregate reports are invaluable for continuous oversight of your email authentication status, confirming policy enforcement, and quickly identifying any unauthorized email sources.
- SPF IP Matching: When verifying SPF, a key detail is confirming that the sending IP address in the email header matches an authorized IP in your SPF record, ensuring proper validation.
Technical article
Documentation from Google Workspace Admin Help explains how to verify SPF, DKIM, and DMARC. For SPF, check email headers for "spf=pass" or "spf=neutral" and confirm the IP address matches your sending server. For DKIM, ensure the DKIM signature is present and valid in email headers, showing "dkim=pass". For DMARC, check headers for "dmarc=pass" and monitor DMARC aggregate reports for authentication results and policy application.
20 Mar 2025 - Google Workspace Admin Help
Technical article
Documentation from Microsoft Learn details how to verify email authentication for SPF, DKIM, and DMARC within Microsoft 365. It advises checking message headers of received emails for "spf=pass", "dkim=pass", and "dmarc=pass" results. It also suggests using online tools for checking DNS records (TXT records) for SPF and DMARC, and specific tools for DKIM key validation.
12 May 2024 - Microsoft Learn
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