The Cold Inbox API
Create, manage, and scale SMTP inboxes via API. Get unlimited domains, 100 inboxes, full SMTP credentials, and real-time provisioning. Perfect for outreach tools, agencies, and developers building email infrastructure.
Cold Email Setup Calculator
Calculate your email infrastructure needs in minutes. Input your domains, client count, and send volume - get exact inbox requirements, plan recommendations, and a ready-to-upload CSV.
Cold Email Spintax Generator
Make every email sound natural and personal. Generate professional spintax variations that keep your core message while avoiding the template feel. Perfect for higher response rates.
More Tools Coming Soon
We're building additional developer tools and APIs. Join our beta to be the first to access new tools and features.
Access All Developer ToolsNeed Custom Development?
We build custom email infrastructure solutions for enterprise clients. From API integrations to white-label platforms, we can help scale your email operations.
without the infra.
