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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.
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.
