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  • DMARC

    Why Your Email Gets Rejected After Moving to DMARC p=reject When Using Proofpoint

    Third-party email security gateways like Proofpoint break DMARC alignment by relaying mail from their own servers, causing legitimate outbound mail to be rejected when DMARC is set to p=reject.

    DMARCGuardian Editorial Team · July 1, 2026

  • DMARC

    Why Finding a Domain Abuse Contact Feels Like Forensic Archaeology - And How to Do It Better

    When you need to report phishing or email abuse, the hardest part is finding the right contact. Here is why existing methods fail and a better workflow that uses DMARC reports to identify senders first.

    DMARCGuardian Editorial Team · July 1, 2026

  • DMARC

    Why Email Authentication Passing Does Not Mean the Sender Is Safe

    Email authentication (SPF, DKIM, DMARC) proves a sender is authorized to use a domain. It does not prove the message is trustworthy. Here is what the difference means for your security posture.

    DMARCGuardian Editorial Team · June 30, 2026

  • Deliverability

    Chat-Based DNS Change Approvals Are a Security Risk

    Approving DNS changes over Slack or Teams is common but risky. Here is what can go wrong, what a secure approval workflow needs, and how to detect problems when they happen anyway.

    DMARCGuardian Editorial Team · June 30, 2026

  • DMARC

    Why Exchange Online Shared Mailboxes Fail DMARC When p=reject Is Enabled

    Exchange Online shared mailboxes send through M365 infrastructure, causing DMARC alignment failures when p=reject is enforced. Here is the root cause and how to fix it.

    DMARCGuardian Editorial Team · June 29, 2026

  • DMARC

    Why Third-Party Senders Break DMARC and How to Fix Subdomain Delegation

    Third-party senders (CRM, marketing, billing) often break DMARC because they send from their own servers using your From domain. This guide explains why it happens and how to fix it using subdomain delegation.

    DMARCGuardian Editorial Team · June 29, 2026

  • DMARC

    Why Your Own DMARC Monitoring Missed That Your Domain Was About to Be Rejected

    A real near-miss reveals why DMARC monitoring setups still miss the signals that predict mail rejection, even when reports are configured.

    DMARCGuardian Editorial Team · June 29, 2026

  • DMARC

    Why a Passing DMARC Record Does Not Mean Your Email Is Secure

    DMARC pass only proves a sender was allowed to use a domain name. It does not prove the message is legitimate, the sender's account is uncompromised, or the content is safe.

    DMARCGuardian Editorial Team · June 29, 2026

  • DMARC

    Can someone spoof my email address even with DMARC?

    DMARC stops direct domain spoofing but has a specific blind spot: forwarded mail and mailing lists that re-envelope the message. Here is exactly what it can and cannot catch.

    DMARCGuardian Editorial Team · June 28, 2026

  • DMARC

    Why a Passing DMARC Record Does Not Mean Your Email Is Safe

    DMARC pass only tells you the sender was authorized to use that domain name. It says nothing about whether the message is legitimate, the account is uncompromised, or the content is safe. Here is what DMARC actually guarantees.

    DMARCGuardian Editorial Team · June 28, 2026

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