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Q & A Email Auth · August 18, 2026

Will DMARC break my email if I set p=reject too quickly?

Yes, if you haven’t fully inventoried all your sending sources. If a legitimate service sends email on your behalf and doesn’t pass SPF or DKIM alignment, p=reject will block those emails. This is why the p=none monitoring phase is critical — use rua reports to identify all sending sources and ensure each passes authentication before moving to reject.

Read the full guide
What Is DMARC? How It Stops Email Spoofing
DMARC is the enforcement layer of email authentication. SPF and DKIM do the checking — DMARC tells receiving servers what to do when they fail, and reports back to you who's sending email using your domain.
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