Email Authentication Articles
Browse our email authentication articles for strategies, checklists, and practical guidance you can apply right away.
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ARC Authentication for Forwarded Mail: The Overlooked Piece of the Puzzle
ARC authentication solves the problem of forwarded mail breaking SPF and DKIM. Here is how it works, who should care, and what senders can actually control.
Best Email Verification Tools in 2026: NeverBounce Alternatives Compared
NeverBounce is one option, but the email verification landscape in 2026 offers better alternatives for specific use cases — better pricing for high volume, better accuracy on Microsoft domains, white-label options for agencies, and integration with modern deliverability workflows.
Gmail's November 2025 Enforcement Shift: From Soft 421 Deferrals to Hard 550 Rejections
Gmail swapped soft 421 deferrals for hard 550 rejections in November 2025. Here is what triggered the change, what it means for your list health, and what to do before your next send.
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Microsoft DMARC Enforcement for Outlook: One Year In, What Senders Actually See
Microsoft DMARC enforcement for Outlook, Hotmail, and Live is active. Learn what changed, how it differs from Gmail, and what to check with SNDS and JMRP.
PCI DSS v4.0 DMARC Requirements: What Payment-Handling Businesses Must Have in 2026
PCI DSS v4.0 requires DMARC for payment-handling businesses. The March 2025 deadline has passed. Learn what auditors check and what p=none means for compliance.
SPF and DKIM Dual Alignment: The Next DMARC Requirement Nobody Is Ready For
DMARC currently passes if SPF or DKIM aligns. The industry is quietly moving toward requiring both. Here is what to audit in your authentication setup now.
Subdomain DMARC: Why Your Unused Subdomains Are Killing Deliverability
Your DMARC record on the root domain does not protect subdomains the way most senders assume. Unused subdomains are an open door for spoofing that tanks deliverability.
Why p=none Is Dying: Preparing for Mandatory p=quarantine and p=reject
DMARC p=none was always meant as a temporary monitoring phase. Google, Microsoft, and PCI DSS v4.0 are forcing the move to enforcement. Here is how.