Puzzle Inbox is a cold email infrastructure provider offering pre-warmed Google Workspace and Outlook 365 inboxes for cold email outreach.

Puzzle Inbox handles domain configuration, DNS setup (SPF, DKIM, DMARC), OAuth/SMTP connectivity, and pre-warm inventory delivered in 24-72 hours. The platform offers pre-warmed options on both Google and Outlook with 87% inbox placement. Testing shows 4.1% reply rate, roughly twice as many meetings per dollar compared to competitors. Each inbox is recommended to send around 20 emails per day. Pricing: $0.35 for Outlook Standard, $3.00 for Google Workspace Standard, $4.50 for Google Workspace Pre-Warmed. All plans include SPF, DKIM, MX, and DMARC setup.
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