Cooper Email
Email inboxes and phone numbers for AI agents
About Cooper Email
Cooper Email is an email API built for AI agents. One HTTP request creates an API key and a real email address for an agent, inbound mail arrives as a signed webhook, and every message across the account is full-text searchable. The point is to give an autonomous agent its own channel to the outside world: it can sign up for services, receive one-time codes, send outreach and confirmations, and read replies, without borrowing a person's inbox or needing a dashboard.
Cooper positions itself as a cheaper, roomier alternative to AgentMail and publishes a side-by-side comparison on its pricing page. Beyond email it can attach a US phone number to an inbox so an agent can receive SMS, with detected OTP codes listed on each message, and voicemail. It is designed to be used by agents directly: there is a hosted MCP server for Claude, ChatGPT, Cursor and Claude Code, an llms.txt machine summary and an OpenAPI spec. Signup is password-free, and the API key is shown once with only its hash stored.
An agent, or a developer on its behalf, posts a username to the onboard endpoint and receives an API key and an address such as research-bot@cooperemail.com. From there it sends mail with a single POST, where a client_id makes each send idempotent, and lists or searches messages with GET requests. For inbound mail you register a webhook and Cooper sends a signed message.received event; agents without a public URL can long-poll a wait endpoint or use server-sent events instead. Paid plans can add custom domains so mail comes from your own domain, buy a US number through the API or MCP to receive texts, and set add-on capacity. A verified human owner can also be registered on an inbox and receive progress or needs-input notes from the agent.
- •One-request inboxes - Create an agent inbox and API key with a single call, with no password and no dashboard step required.
- •Signed webhooks and waiting - Inbound mail triggers signed webhooks, with wait endpoints and server-sent events for agents that cannot expose a URL.
- •Account-wide search - Every message in every inbox is indexed for full-text search, so an agent can find a thread later without paging.
- •Hosted MCP server - Connect Claude, ChatGPT, Cursor or Claude Code to create inboxes, send mail and wait for codes as tool calls.
- •SMS and voice on agent numbers - Starter and Pro can buy US local numbers that receive texts, surface OTP candidates and take voicemail.
- •Owner-in-the-loop updates - A verified owner's reply becomes a task for the agent, and the agent can send the owner progress, done or error notes.
Cooper Email is for developers building agents that need to act on the open internet: sign up for accounts, collect verification codes, send and receive email with people, or talk to other agents across different stacks. Teams running a production support or invoice-handling agent can give it an address on their own domain on the Starter plan. Products that give every customer or workflow its own agent inbox can use the Pro plan's 300 inboxes and 200 domains. The free plan, with five inboxes and no card, suits individual builders experimenting with a few agents. Note that Cooper states it does not have a SOC 2 report.
Pricing
$0 - $99/mo
- Free$0/mo
- Starter$12/mo
- Pro$99/mo
- EnterpriseContact sales
From the vendor pricing page, 2026-11-09
