CapiMail: Transactional email API for developers and AI agents

Hey Product Hunt 👋 I'm Lelianto, maker of CapiMail.

I built CapiMail because the email your product depends on (OTP codes, password resets, verification links, receipts) shouldn't be an afterthought, and it should work just as well when an AI agent is the one sending it.

What it does:

• One HTTP endpoint to send from your own verified domain

• Idempotency keys + a durable retry queue, so nothing gets sent twice

• Real delivery events: "delivered" only when the provider confirms it

• Agent-ready: official SDKs (JS, Python, PHP), an MCP server (npx @capimail/mcp), OpenAPI and llms.txt

• Test mode (cm_test_ keys) runs the full lifecycle with signed webhooks, without sending real email

One honest limitation: payments currently only support QRIS (Indonesia's QR payment standard), so international cards aren't supported yet. You can still try the whole API in test mode without paying anything. If payment is a blocker for you, tell me which method you'd need, it helps us prioritize.

I'd love your feedback on: what's missing for you to switch from your current email provider? And if you're building agents, how do you want them to handle email?

I'll be here all day answering questions 🙌

Forum Threads

p/capimail

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2d ago

What do you wish transactional email APIs did better for AI agents?

We're launching CapiMail here on Nov 13, and I'd love to hear from people who send OTPs, password resets, receipts or alerts, especially if an AI agent is doing the sending.

A few questions:

What's the most painful part of your current email provider: setup, deliverability, debugging, or pricing?

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