Create email inboxes for AI agents via MPP-payable API
What it does
AgentMail's Create Inbox endpoint provisions new email inboxes programmatically for AI agents. It is part of the broader AgentMail API, which provides a full email infrastructure designed specifically for autonomous agents — including inbox management, sending/receiving messages, threads, drafts, attachments, custom domains, webhooks, and allow/block lists. The endpoint is served over the MPP (Micropayment Protocol) gateway at `https://mpp.api.agentmail.to/v0/inboxes` and accepts POST requests with an optional JSON body specifying username, domain, display name, and client ID. The default domain is `agentmail.to`, and usernames are randomly generated if not specified.
Pricing is fixed at 2 units per inbox creation (per the `x-payment-info` in the OpenAPI spec), settled via the Tempo method on chain ID 4217. Most read operations (list inboxes, get inbox, list messages, get threads, etc.) are priced at 0, while write operations like sending messages, creating drafts, and creating domains carry small fixed charges (e.g., 0.01 for sending, 10 for domain creation). The API uses Bearer token authentication. The full OpenAPI 3.1 spec covers dozens of endpoints across inboxes, messages, threads, drafts, domains, pods, webhooks, lists, and metrics — all accessible through the same MPP gateway.
AgentMail is a Y Combinator-backed company that raised $6M in seed funding. The service provides Python, TypeScript, and cURL SDKs, plus an MCP integration. The MPP challenge was successfully captured, confirming the endpoint is live and accepting payment-gated requests.
Capabilities
Use cases
- —Give each AI agent its own email address for sending and receiving messages
- —Automate email-based workflows like customer support, outreach, or notifications
- —Enable agent-to-agent communication over standard email protocols
- —Receive and process inbound emails with webhooks for real-time event handling
- —Manage email threads, drafts, and attachments programmatically from agent code
Fit
Best for
- —AI agent developers needing dedicated email inboxes per agent
- —Autonomous agent frameworks requiring email send/receive capabilities
- —Applications that need programmatic email inbox creation at scale
Not for
- —Human-facing email clients or webmail replacements
- —Bulk marketing email campaigns (this is an inbox API, not a mass-send service)
- —Use cases requiring IMAP/POP3 protocol access
Quick start
curl -X POST https://mpp.api.agentmail.to/v0/inboxes \
-H "Authorization: Bearer <MPP_TOKEN>" \
-H "Content-Type: application/json" \
-d '{"username": "my-agent", "domain": "agentmail.to"}'Example
Request
{
"domain": "agentmail.to",
"username": "my-agent",
"display_name": "My Agent <my-agent@agentmail.to>"
}Response
{
"pod_id": "pod_abc123",
"inbox_id": "my-agent@agentmail.to",
"created_at": "2025-01-15T10:30:00Z",
"updated_at": "2025-01-15T10:30:00Z",
"display_name": "My Agent <my-agent@agentmail.to>"
}Endpoint
Quality
Full OpenAPI 3.1 spec with detailed schemas and pricing info is available. MPP 402 challenge was captured and confirms the endpoint is live on Tempo. Response examples are inferred from schema (not directly observed), and external docs at docs.agentmail.to were not crawled.
Warnings
- —Response example is inferred from the OpenAPI schema, not captured from a live successful call
- —External documentation at docs.agentmail.to was not crawled; detailed usage guides may exist there
- —Pricing units are not explicitly labeled as USD or any specific currency in the OpenAPI spec
Citations
- —Create Inbox endpoint has a fixed price of 2 via MPPhttps://mpp.api.agentmail.to
- —MPP challenge captured with method=tempo, intent=charge, chainId=4217https://mpp.api.agentmail.to/v0/inboxes
- —AgentMail raised $6M in Seed Funding and is backed by Y Combinatorhttps://mpp.api.agentmail.to
- —Default domain is agentmail.to; username is randomly generated if not specifiedhttps://mpp.api.agentmail.to
- —Send Message endpoint priced at 0.01; Create Domain priced at 10https://mpp.api.agentmail.to