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Email Authentication & Deliverability Guides

Practical, RFC-grounded engineering guides on SPF, DKIM, DMARC policies, aggregate RUA reporting, and domain security operations.

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SPF Troubleshooting••7 min read

How to Fix the SPF 10-DNS-Lookup Limit (PermError Troubleshooting Guide)

Why RFC 7208 caps SPF at 10 DNS lookups, which mechanisms count toward the limit, why SPF flattening breaks, and how to fix SPF PermError safely.

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DMARC Enforcement••6 min read

DMARC Policies Explained: p=none vs p=quarantine vs p=reject (Safe Rollout Guide)

Understand the difference between DMARC p=none, p=quarantine, and p=reject, how pct= and sp= tags work, and how to roll out DMARC enforcement without blocking legitimate email.

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Alignment & Deliverability••5 min read

How to Troubleshoot SPF, DKIM, and DMARC Alignment Failures

Why DMARC fails even when SPF or DKIM says PASS: learn how RFC5322.From identifier alignment works, how to read Authentication-Results headers, and how to fix misalignment.

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DMARC Reporting••5 min read

DMARC Aggregate Reports (RUA) Explained: How to Read XML Reports and Spot Spoofing

Learn what DMARC RUA aggregate reports contain, how to read the RFC 7489 XML schema, the difference between RUA and RUF, and how to identify spoofing vs shadow IT.

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Cloud Email Setup••5 min read

Google Workspace & Microsoft 365 SPF, DKIM, and DMARC Setup and Troubleshooting

Complete DNS configuration guide for Google Workspace and Microsoft 365: exact SPF includes, 2048-bit DKIM selector setup, DMARC records, and common coexistence errors.

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MSP & Agency Operations••5 min read

Email Authentication Monitoring for MSPs and Agencies: A Practical Multi-Tenant Workflow

How MSPs, MSSPs, and digital agencies audit, standardize, and continuously monitor SPF, DKIM, and DMARC across dozens of client domains without manual DNS checks.

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Email Authentication••6 min read

DKIM vs DMARC: What's the Difference? Do You Need Both?

DKIM vs DMARC explained: what each does, how they work together with SPF, and why you need both to protect your domain from spoofing.

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Email Authentication••5 min read

Gmail & Yahoo Sender Requirements 2026: The Complete Checklist for Every Sender

Gmail & Yahoo sender requirements 2026: bulk sender rules, one-click unsubscribe, 0.3% spam threshold, DMARC alignment, and a compliance checklist.

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Email Authentication••3 min read

Why Are My Emails Going to Spam? 7 Real Causes (and How to Fix Each One)

A practical, technical breakdown of the most common reasons legitimate business emails land in spam -- and exactly how to fix each one.

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Email Authentication••3 min read

SPF, DKIM, and DMARC Explained Simply (No Jargon)

A plain-English explanation of SPF, DKIM, and DMARC -- what each one does, how they work together, and why your domain needs all three.

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