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>log in to commentHi all, I built Cooper Email. Give every AI agent its own inbox. I'll be around in the comments, ask me anything about how it works.
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Cooper Email provides an API that gives AI agents a real email inbox (and optional phone number) with webhooks and full-text search.
- for
- Developers building autonomous AI agents that need email or SMS communication.
- pricing
- freemium
- license
- MIT
Key features
- One-click inbox creation — POST /onboard returns an API key and a unique @cooperemail.com address in a single request.
- Signed inbound webhooks — Incoming email arrives as a signed webhook for immediate processing by the agent.
- Full-text searchable mail — All messages are indexed with SQLite FTS5, searchable via GET /search.
- Custom domains — Starter and Pro plans support custom domains with automatic DNS when using Cloudflare.
- Phone numbers & SMS — Buy US numbers ($3/mo each) to receive texts stored as inbox messages with webhook alerts.
- Hosted MCP integration — Connect agents via the hosted MCP server for Claude, ChatGPT, Cursor, and other tools.
Use cases
- Agent sends outreach emails and receives replies via webhook
- Agent processes OTP codes from SMS for verification
- Human-in-the-loop tasks where email replies become structured tasks
- Testing CI pipelines with temporary inboxes per run
Cooper Email pricing
- Free$05 inboxes · 5,000 emails/month · no daily cap · no custom domains
- Starter$12/mo/month25 inboxes · 25,000 emails/month · 15 custom domains · Buy US numbers
- Pro$99/mo/month300 inboxes · 250,000 emails/month · 200 custom domains · 3 US numbers included
Cooper Email vs alternatives
 Cooper Email |  Smithery |  PostalDataPI |  Selvedge |  Testera IO | |
|---|---|---|---|---|---|
| Best for | API inboxes for AI agents | MCP server hosting | Geolocation data | Agent memory | Automated testing |
| Pricing | Freemium | Free | Subscription | Free | Free |
| DevHunt upvotes | 1 | 0 | 76 | 38 | 35 |
| Launched | Oct 2031 | — | Apr 2026 | Oct 2026 | Aug 2026 |
- Cooper Email vs Smithery: Smithery is a registry for hosting MCP servers, not an email API.
- Cooper Email vs PostalDataPI: PostalDataPI provides global address data, not email inboxes for agents.
- Cooper Email vs Selvedge: Selvedge offers memory storage for agents, whereas Cooper Email handles email communication.
- Cooper Email vs Testera IO: Testera IO focuses on QA automation, not email or SMS inbox services.
Cooper Email FAQ
How do I give my AI agent an email address?+
POST https://cooperemail.com/api/v1/onboard with a username; the response includes an API key and username@cooperemail.com.
Can my agent receive text messages?+
Yes, on Starter and Pro plans you can purchase a US number ($3 / month) and inbound SMS are stored as inbox messages with webhooks.
What limits apply on the Free plan?+
Free includes 5,000 emails/month, 5 inboxes, no daily cap, and no custom domains.
How are overage limits handled?+
When a limit is exceeded the API returns HTTP 402 with an upgrade URL; add-ons can be purchased on Starter and Pro.
Is there a trial or card required?+
Free tier requires no credit card; paid plans start at $12/mo.
Summarized by DevHunt from cooperemail.com · Oct 24, 2026. Details may change; check the official site.
