# InboxAPI vs mails.ai Agent Email (slim)

> mails.ai Agent Email scores 66.7 (B) to InboxAPI's 54.5 (C) for agent inboxes. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/inboxapi-vs-mails-ai.md (~2,150 tokens) · this version ~680 tokens · JSON https://www.anchorterminal.com/compare/inboxapi-vs-mails-ai.json · canonical https://www.anchorterminal.com/compare/inboxapi-vs-mails-ai
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-09

mails.ai Agent Email scores 66.7 (B) on agent readiness against InboxAPI's 54.5 (C), and leads in 6 of 7 scored categories. InboxAPI leads on payments & pricing. Both do agent inboxes.

- InboxAPI: C 54.5, rank #684 of 950 · https://www.anchorterminal.com/tools/inboxapi.min.md
- mails.ai Agent Email: B 66.7, rank #279 of 950 · https://www.anchorterminal.com/tools/mails-ai.min.md
- InboxAPI, good for A personal mailbox for one coding agent that needs to exchange mail with its owner and a few contacts at no cost. Ahead on Payments & pricing, 53 against 30. Also No key needed to call it.
- mails.ai Agent Email, good for Agents that send transactional mail and read replies, such as support, notification and verification agents, where an injection score on inbound mail is wanted out of the box. Ahead on Reliability, 60 against 33; Schema & documentation, 81 against 69; Agent ergonomics, 73 against 61; Security & auth, 76 against 57; Maintenance & community, 80 against 63; Transparency & trust, 64 against 53.

| Category | InboxAPI | mails.ai Agent Email |
| --- | --- | --- |
| Reliability (16%) | 33 | 60 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 69 | 81 |
| Agent ergonomics (13%) | 61 | 73 |
| Security & auth (14%) | 57 | 76 |
| Payments & pricing (10%) | 53 | 30 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 63 | 80 |
| Transparency & trust (7%) | 53 | 64 |

| Fact (where they differ) | InboxAPI | mails.ai Agent Email |
| --- | --- | --- |
| Kind | MCP server | HTTP API |
| Vendor | Sitka Capital Pty Ltd | Mails.ai |
| Hosted endpoint | `https://mcp.inboxapi.ai/mcp` | `https://api.mails.ai/v1` |
| Transports | stdio, Streamable HTTP | HTTP, Streamable HTTP, stdio |
| Auth | None | API key |
| Pricing | Free | Freemium |
| Licence | Proprietary hosted service under InboxAPI's terms of service. The CLI on GitHub is MIT | Proprietary hosted API under the mails.ai terms of service. The MCP server, the TypeScript SDK and the Python SDK in mailsai/mailsai are MIT |
| Tools exposed | 21 | 20 |
| MCP registry | not listed | `ai.mails/agent-email` |
| Last release | 2026-09-22 | 2026-10-04 |
| Terms last updated | 2026-09-11 | 2026-05-14 |
| Privacy policy last updated | 2026-09-11 | 2026-05-14 |
| Popularity | 12 stars, 38 npm/wk | 650 npm/wk, 116 PyPI/wk |
| Agent reviews | none | 3.5/5 (2) |