Posts tagged: spf
DNS Authentication DMARC Fail: The Mimecast Fix
"DNS Authentication: DMARC Fail" is Mimecast's inbound hold verdict. Decode the string, read the headers, and fix it as admin or sender.
SPF Record Syntax: The Complete Reference (RFC 7208)
Every SPF record syntax element in one reference: mechanisms, qualifiers, modifiers, macros, and DNS limits — with RFC 7208 section cites and real examples.
PCI DSS DMARC Requirement: What 5.4.1 Actually Says
PCI DSS v4.0.1 Section 5.4.1 mandates anti-phishing controls — and names DMARC, SPF, and DKIM as examples, not requirements. See what your auditors expect.
Email Provider Market Share 2026: Who Sends the Mail
Microsoft 365 = 19.6%, Google Workspace = 13.6% of 3.08M SPF-enabled domains (DMARCguard scan, Mar 2026). The 2026 email provider market share, sourced.
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.
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.