How to identify and handle spoofed emails violating DMARC policies?

Marketer from Email Geeks shares that you can run an ARIN search on the IPs sending the emails to find the owner and the abuse contacts.

Email marketer from SparkPost explains that email forwarding can often break DMARC authentication, as the forwarded email may no longer align with the original sender's SPF or DKIM records. They suggest using techniques like SRS (Sender Rewriting Scheme) to mitigate this issue.

Email marketer from Agari explains that implementing a strict DMARC policy (p=reject) can significantly reduce the risk of phishing and spoofing attacks, protect your brand reputation, and improve email deliverability. They advise carefully monitoring DMARC reports before implementing a 'reject' policy to avoid unintended consequences.

Email marketer from StackExchange user 'mailauthguru' explains that DMARC failures can occur for various reasons, including SPF failures due to incorrect DNS records, DKIM signature verification issues, and forwarding scenarios that break authentication. Understanding the specific failure reason is crucial for effective troubleshooting.

Marketer from Email Geeks suggests checking your SPF/DKIM/DMARC policy to ensure you're not an easy spoof target. Mentions the possibility of someone using your domain for pen-testing, like with KnowBe4.

Email marketer from EasyDMARC explains that common causes of DMARC failure include misconfigured SPF records, DKIM signing issues, and legitimate emails being forwarded in a way that breaks authentication. They suggest carefully reviewing your email infrastructure and authentication settings to identify and fix these issues.

Email marketer from Reddit user u/email_expert emphasizes the importance of regularly monitoring DMARC reports to identify potential spoofing attempts and ensure that legitimate emails are properly authenticated. They recommend using a DMARC reporting tool to simplify the process.

Email marketer from Mailjet shares that implementing DMARC involves setting up SPF and DKIM, publishing a DMARC record in your DNS, and monitoring DMARC reports to identify and address spoofing attempts. They recommend starting with a 'p=none' policy and gradually moving to 'p=quarantine' or 'p=reject' as you gain confidence.

Email marketer from Email Marketing Forum user 'emailpro' discusses the importance of correct DMARC record syntax. They recommend validating the DMARC record using online tools to prevent errors that could impact email deliverability. Common errors include typos and incorrect tag values.

Email marketer from Proofpoint shares that responding to DMARC violations involves analyzing DMARC reports to identify the source of the spoofing, taking steps to remediate the issue (e.g., updating SPF records, fixing DKIM signatures), and adjusting your DMARC policy to reject unauthorized emails.

Expert from Word to the Wise explains the importance of DMARC alignment (SPF and DKIM alignment) to ensure legitimate emails pass DMARC checks. She explains that understanding alignment is key to preventing legitimate mail from being inadvertently blocked.

Expert from Email Geeks explains it sounds like you're randomly chosen to be the spoofed domain. If your DMARC policy is set to reject, alert your support and security teams to watch for or expect an increase in help requests or intrusion attempts.

Expert from Spam Resource explains that DMARC aggregate reports are essential for understanding DMARC performance and identifying potential issues. They outline how to interpret these reports to identify spoofing attempts and authentication failures, providing tips on how to action this data.

Expert from Word to the Wise discusses the differences between DMARC 'quarantine' and 'reject' policies, advising a gradual transition from 'quarantine' to 'reject' to minimize the risk of blocking legitimate emails while still protecting against spoofing.

Documentation from RFC7489 describes the DMARC (Domain-based Message Authentication, Reporting & Conformance) standard. It provides technical specifications for how email receivers should handle messages that fail authentication checks and how domain owners can receive reports on authentication results.

Documentation from DMARC.org explains that a DMARC policy allows domain owners to instruct recipient mail servers on how to handle emails that fail DMARC checks (none, quarantine, reject). They emphasize that the 'reject' policy is the strongest, preventing unauthorized emails from reaching the inbox.

Documentation from Google Workspace Admin Help explains that DMARC reports provide insights into email authentication failures, helping identify sources spoofing your domain. It recommends analyzing these reports to understand the nature and origin of the spoofing attempts and adjust your DMARC policy accordingly.

Documentation from Cloudflare explains the process of setting up a DMARC record in Cloudflare's DNS management interface. It provides step-by-step instructions on how to add a TXT record with the correct DMARC syntax and values.

Documentation from Microsoft explains you can use the Threat Explorer feature in Microsoft Defender for Office 365 to investigate email authentication results, including DMARC failures. This allows you to identify spoofing attempts and take appropriate action.