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Email Deliverability Checklist: 20 Checks Before Every Campaign

ZeroPhantom 2026-02-27 5 min read

Poor deliverability is almost always preventable. Here's the complete pre-send checklist.

Authentication

  • ☑ SPF valid, under 10 lookups
  • ☑ DKIM signing active (2048-bit)
  • ☑ DMARC published (p=quarantine minimum)
  • ☑ PTR record matches sending domain

Reputation

  • ☑ Not blacklisted (MXToolbox check)
  • ☑ Gmail domain reputation Medium or High
  • ☑ Warmup complete for new domains
  • ☑ Sending from dedicated IP

List Quality

  • ☑ List verified in last 30 days
  • ☑ Hard bounces from last campaign removed
  • ☑ Unsubscribes processed
  • ☑ No purchased or harvested addresses
  • ☑ Inactives (6+ months) removed or suppressed

Content

  • ☑ Subject line under 50 chars, no trigger words
  • ☑ 60%+ text-to-image ratio
  • ☑ Plain text version included
  • ☑ Unsubscribe link functional
  • ☑ Physical address present (CAN-SPAM)

Testing

  • ☑ Seed list test (Gmail, Outlook, Yahoo)
  • ☑ SpamAssassin score below 3.0
  • ☑ Renders correctly on mobile
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