Shipped a temp email API for tests + AI agents. $15/mo, MCP built in.
After 6 days of solo building, I shipped MailSink yesterday.
What it does: programmatic temporary email inboxes. REST API + MCP server built in. Dispatch an inbox, catch the verification email, extract the OTP code. All via HTTP.
Why: testing email flows in CI has been painful for years. MailSlurp is $79/mo, Mailtrap's API isn't built for AI agents. Built what I wished existed.
The twist: MCP server ships in the box. So Claude Code, Cursor, Windsurf, any MCP client can sign up for real services during autonomous workflows. Not a hack, not a wrapper. Native.
Stack:
- Cloudflare Workers (API + email routing)
- D1 for metadata, R2 for storage
- Sub-20ms p50, 320+ edge locations
- OTP + magic-link extraction for Stripe, GitHub, Clerk, Supabase, Auth0, Resend, AWS
Pricing:
- Free: 3 inboxes, 100 msgs/mo
- Pro: $15/mo unlimited
- BYOD on Pro+ (bring your own domain)
Live at https://mailsink.dev. Free tier, GitHub OAuth, you're in in 10 seconds.
Would love honest feedback, especially on:
- Does the API shape make sense?
- Is the pricing right for indie use?
- What would break your workflow?
First open stable release. Still learning what breaks.
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Strong build — but “MailSink” is holding it back.
It sounds disposable, while your product is actually infra for testing + AI workflows.
That mismatch alone will cap adoption more than features or pricing.
If you’re planning to push this, fixing the name will move the needle fastest.
I work with clean, brandable .coms in dev/API space — can share a few that fit this exactly.
Thanks, but MailSink is the right name for what this does. Sink = where mail drains. That's literally what a temp inbox is. The "disposable" read is the point, not a weakness. MailSlurp uses the same framing and charges $79/mo. Keeping the name.
Fair — that framing makes sense for dev workflows.
Out of curiosity, if you ever expand beyond temp inbox (API infra / testing layer), would you keep MailSink or split into a broader brand?
Seen a few tools hit that ceiling later — curious how you’re thinking about it.
Shipping a native MCP server for temp emails is a game-changer for autonomous coding agents, anhphong. You've solved a massive friction point by making it $15/mo instead of $79/mo while specifically targeting the AI agent workflow that legacy tools haven't touched yet.
I’m currently running a project in Tokyo (Tokyo Lore) that highlights high-utility developer tools and technical logic just like MailSink. Since you're already disrupting the pricing model and infrastructure for automated email testing, entering this round could be a perfect way to show off your edge-first architecture while your odds are at their absolute peak.
Thanks for the note. Not looking to enter showcase rounds right now, staying focused on shipping and user feedback.