# Email inbox APIs for AI agents (slim)

> 1 agent inbox APIs ranked by the Anchor benchmark. Leader AgentMail API + MCP (BB). APIs that give an agent its own email address, so it can send, receive replies and carry a thread on over days. Compared on how an inbox is created, how replies reach the agent (webhooks, websockets, polling), threading, custom domains and price per inbox.

- Full: https://www.anchorterminal.com/categories/agent-inboxes.md (~750 tokens) · this version ~230 tokens · JSON https://www.anchorterminal.com/categories/agent-inboxes.json · canonical https://www.anchorterminal.com/categories/agent-inboxes
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-04

- Tools: 1 · agent-ready (BB+): 1 · accept x402: 1 · JSON: https://www.anchorterminal.com/api/v1/tools.json · by capability: https://www.anchorterminal.com/api/v1/capabilities.json
- Capabilities: email.inbox, email.send, email.inbound, email.threads, email.domains

| # | Tool | Grade | Score | Confidence | x402 | Auth | Where | Slim |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 44 | AgentMail API + MCP | BB | 75 | medium | yes | OAuth or key | hosted + local | https://www.anchorterminal.com/tools/agentmail.min.md |