# Email inbox APIs for AI agents

> 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.

- Canonical: https://www.anchorterminal.com/categories/agent-inboxes
- Markdown: https://www.anchorterminal.com/categories/agent-inboxes.md (~750 tokens)
- Slim: https://www.anchorterminal.com/categories/agent-inboxes.min.md (~230 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/categories/agent-inboxes.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-04

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.

- Tools ranked: 1 · agent-ready (BB or better): 1 · accept x402: 1 · hosted endpoints: 1 · desk reviews by the panel: 8
- JSON: https://www.anchorterminal.com/api/v1/tools.json (list) · https://www.anchorterminal.com/api/v1/rankings.json (ranked) · https://www.anchorterminal.com/api/v1/x402.json (payable) · https://www.anchorterminal.com/api/v1/capabilities.json (by capability)
- Grades run AA, A, BB, B, C, D, E, F · methodology: https://www.anchorterminal.com/benchmark/

- Capabilities in this category: email.inbox, email.send, email.inbound, email.threads, email.domains
- https://letme.dev/email.inbox picks the top-graded tool in this list and says how to call it direct; calling through letme comes later (https://www.anchorterminal.com/letme/index.md)

## Ranking

| # | Tool | Vendor | Kind | Category | Grade | Score | Confidence | x402 | Auth | Where | Reviews | Page |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 44 | AgentMail API + MCP | AgentMail | HTTP API | Inboxes | BB | 75 | medium | yes ($2/call) | OAuth or key | hosted + local | 3.1/5 (8) | https://www.anchorterminal.com/tools/agentmail.md |

Scores are from public evidence against the published checklist (https://www.anchorterminal.com/benchmark/), with Performance and Task success pending. p95 latency and context cost come from our probes, which haven't run yet.

## Summaries

### 44. AgentMail API + MCP, BB (75)

Email inboxes for agents over REST. Inbox creation, threads, drafts and labels built for agents, with `extracted_text` that drops quoted history. Email sending was down for 8 hours 7 minutes on 19 August 2026.

- Page: https://www.anchorterminal.com/tools/agentmail · Markdown: https://www.anchorterminal.com/tools/agentmail.md · JSON: https://www.anchorterminal.com/api/v1/tools/agentmail.json
- Capabilities: email.inbox, email.send, email.inbound, email.threads, email.domains, email.analytics · endpoint: `https://api.agentmail.to/v0`