MailVitalsEmail deliverability
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Module 10 · Lesson 29 of 37

Step-by-Step Diagnosis

Part of The Complete Email Deliverability Course — Troubleshooting Deliverability.

When inbox placement drops, follow this sequence:

  1. 🔐 Check authentication — Verify SPF, DKIM, DMARC pass rates
  2. ⭐ Check reputation — GPT compliance, SNDS, Sender Score
  3. 🚫 Check blocklists — Spamhaus, Barracuda, SpamCop via MXToolbox
  4. 📝 Check content — Text-to-image ratio, link reputation, HTML structure
  5. 📋 Check list quality — Bounce spikes, spam traps, complaint increases
  6. 📊 Check sending patterns — Volume spikes, gaps, segment quality
  7. ⚙️ Check infrastructure — DNS records, TLS, server configuration

Reading email headers:

  • Read Received headers bottom-to-top
  • Bottom = originating server; each subsequent = next hop
  • Check Authentication-Results for verdicts
  • Verify originating IP matches authorized infrastructure

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example.comWatching
  • SPFpass
  • DKIMpass
  • DMARCp=none
  • Blacklists0 of 34

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