Copy EmailChecker?
Fast, Accurate Email Checker API You Can Trust. Bulk Email list verification, 99% Guaranteed Deliverability.
Build me a Developer Tools web app like EmailChecker. EmailChecker does: Fast, Accurate Email Checker API You Can Trust. Bulk Email list verification, 99% Guaranteed Deliverability. It reportedly makes about $399/mo, so the core idea clearly has demand — I want a lean version I can run and charge for. Start from the open-source project mettle/sendportal (https://github.com/mettle/sendportal) — reuse what fits, strip its branding, and build the specifics below on top of it. Requirements: - Import subscribers, manage lists/segments. - Drag-and-drop email builder, send/schedule campaigns. - Open/click tracking and a simple automation (welcome series). Also: - Clean, modern, responsive UI with a thoughtful landing page. - Email/password auth and a simple paid tier (Stripe test mode) so it's ready to charge. - A README covering setup, environment variables, and how to deploy. Ship a working MVP I can run locally first, then help me deploy it.
Start from this instead of a blank page
Also worth copying in Developer Tools
Questions
Can I really build something like EmailChecker?
Yes. EmailChecker is a developer tools product doing ~$399/mo — the core loop is well understood. With the prompt on this page and the open-source repo mettle/sendportal as a base, a coding agent like Claude Code or BuildCheap can get you a working MVP in a weekend.
How much does EmailChecker make?
Around $399/mo based on public revenue data. That's the whole point of CopyMRR — you're copying something with proven demand, not guessing.
What repo does this start from?
mettle/sendportal (2,136★). "Clone & ship" imports it straight into BuildCheap so you start from a running app, then adapt it.
Is this affiliated with EmailChecker?
No. CopyMRR indexes public revenue data and points you at open-source building blocks. Build your own thing — don't copy their brand or content.
New winners in your inbox, weekly
Get the freshest revenue-making SaaS + the open-source repo to clone each one, before everyone else does.