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Cold Email Provider Evaluation Checklist: 15-Point Due Diligence 2026

By Puzzle Inbox Team · May 14, 2026 · 8 min read

Cold email provider evaluation checklist with 15 specific due diligence points. Use this before committing to any cold email infrastructure provider.

The 15-Point Cold Email Provider Evaluation Checklist

Cold email infrastructure provider selection is a high-stakes decision. Bad provider choices cost pipeline, operational time, and migration overhead. Use this 15-point checklist to evaluate any cold email provider before committing.

Infrastructure Authenticity (Points 1-4)

  1. Real GWS or MS365? Request admin console access. Real accounts give admin.google.com or admin.microsoft.com.
  2. Dedicated or shared? Ask about infrastructure isolation from other customers.
  3. Pre-warming included? Verify warmup is actually included, not marketing claim.
  4. DNS authentication? SPF, DKIM, DMARC correctly configured on delivery.

Pricing Transparency (Points 5-7)

  1. Per-inbox all-in cost? Include warmup, support, replacement churn.
  2. Bulk pricing structure? Volume discounts documented.
  3. Cancellation and refund policy? Written terms available.

Operational Capability (Points 8-11)

  1. Support speed? WhatsApp/chat response times documented.
  2. Provisioning time? Hours from order to ready-to-send.
  3. Account replacement? Policy for suspended inboxes.
  4. Scale capacity? Can they deliver 100+ inboxes if you grow?

Deliverability Evidence (Points 12-13)

  1. Published deliverability data? Or willingness to share benchmarks.
  2. Independent reviews? G2, Capterra, Reddit presence.

Platform Coverage (Points 14-15)

  1. Google Workspace option? Authentic GWS available.
  2. Microsoft 365 option? Authentic MS365 available for diversification.

Scoring Framework

  • 13-15 points: Excellent provider fit
  • 10-12 points: Acceptable with specific considerations
  • 7-9 points: Risky choice, evaluate alternatives
  • Under 7 points: Do not proceed

Providers That Score High

Puzzle Inbox (15 points): Authentic GWS + MS365, pre-warming included, WhatsApp support, fast provisioning, dual-platform, independent reviews, replacement policy.

Mission Inbox (14 points): Enterprise features, SLAs, comprehensive documentation.

InboxKit (13 points): Google Cloud partner, authentic infrastructure, Azure option for enterprise.

Providers That Score Lower

AI-branded providers (6-8 points): Fail on deliverability data publishing and pricing transparency.

Budget shared infrastructure providers (5-8 points): Fail on dedicated infrastructure, pre-warming, and deliverability evidence.

Use this 15-point checklist before any cold email infrastructure commitment. High-scoring providers like Puzzle Inbox pass all points. Low-scoring providers signal risk.
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