Posts tagged: email-authentication
How to Read a DMARC Aggregate Report (XML Made Simple) [2026]
Read DMARC aggregate reports field by field. Annotated XML, Google vs Microsoft variants, and a live drawer demo. Free analyzer inside.
TLS-RPT Reports: SMTP TLS Reporting Explained (RFC 8460)
TLS-RPT reports tell you when SMTP TLS fails between mail servers. See an annotated RFC 8460 JSON example, every result type, and how to set it up.
What Is ARF in Email? Abuse Reporting Format
ARF (Abuse Reporting Format, RFC 5965) is the standard for DMARC forensic reports and email feedback loops. Annotated sample inside.
DKIM2 Explained: The 2026 Successor to ARC and DKIM
DKIM2 is the IETF's per-hop chained-signature successor to ARC and DKIM. Five drafts, four contested questions, and what email admins track in 2026.
DANE Email Authentication: Why 0.0% of Domains Use It
DANE binds TLS certificates to DNS via DNSSEC — but only 30 of 5.5M scanned domains use it. Inside RFC 7672, TLSA records, NIS2, and DANE vs MTA-STS.
ARC Email Authentication: Forwarded Mail in 2026
ARC email authentication preserves SPF, DKIM, and DMARC verdicts across forwarding hops in 2026. See real i=1 and i=2 headers, cv=fail debugging, and trusted-sealer fixes. Analyze a chain free.
Microsoft DMARC: Office 365 Setup Guide 2026
Microsoft enforces DMARC for Outlook senders since May 5, 2025. Set up DMARC for Office 365 and Microsoft 365 step-by-step with DNS examples. Configure now.
Google, Yahoo & Microsoft DMARC Requirements
Google, Yahoo, and Microsoft now require DMARC for bulk senders — including Gmail's 2025 SMTP rejection escalation. See the full compliance checklist.
DMARC Fails on Forwarded Emails: Why ARC Is the Fix
Forwarded emails fail DMARC because SPF breaks in transit. See why, when DKIM survives, and how ARC seals the chain across every forwarding hop.
SPF Flattening: Fix Too Many DNS Lookups (2026)
148,655 domains exceed the SPF 10-lookup limit. Learn what SPF flattening is, when to use it, 4 safer alternatives, and step-by-step fixes. Check free.
SPF Softfail vs Hardfail: Which to Use?
53.6% of domains use SPF softfail, 40.2% use hardfail. Learn how each qualifier works, how DMARC changes the equation, and which to choose. Check your SPF free.
SPF PermError: How to Find and Fix It (2026 Guide)
SPF PermError breaks DMARC alignment and kills deliverability. Learn the 5 causes, step-by-step fixes, and platform-specific examples. Check your SPF free.
DKIM Fail: How to Fix Alignment and Verification Errors
DKIM failing? Learn why DKIM alignment breaks, how to fix body hash errors, and how to configure third-party senders. Step-by-step guide with CLI commands.
DMARC Quarantine/Reject Policy Not Enabled: Fix It
See 'DMARC quarantine/reject policy not enabled'? Learn what it means, why it matters, and how to fix it step by step for any DNS provider. Free checker included.
DMARC Fail: 7 Causes & How to Fix Each (2026 Guide)
DMARC failed? Fix it fast: 7 causes (SPF/DKIM misalignment, third-party senders, forwarding) with diagnose steps, fixes, and a free DMARC checker.