Atomic Mail MCP
The Atomic Mail MCP server: an agent creates its own atomicmail.ai inbox and works with mail through JMAP with no human involved.
- 256 ★ on the repository
- Last commit
Broad access
Why this level
- The agent reads and sends mail itself with no human involved, including from your domain.
- Mail and mailbox credentials are stored in an external service.
Install
- Works in
Manual install
{"mcpServers":{"atomicmail":{"command":"npx","args":["-y","@atomicmail/mcp-github"]}}}The MCP configuration snippet from the README.
Access and checks
How we reviewBroad accessThe tool can change data, run commands or handle secrets.
- The agent reads and sends mail itself with no human involved, including from your domain.
- Mail and mailbox credentials are stored in an external service.
This is third-party code. Review the repository files before installing.
What it does
Atomic Mail Agentic is an email service for autonomous AI agents. An agent registers its own `@atomicmail.ai` inbox and runs it end to end: reads and sends mail, creates drafts, manages threads and searches. The service is built on JMAP (RFC 8620), so the agent gets a full mailbox API that models know well. Access is protected by a proof of work signup: it limits abuse with no CAPTCHAs or manual approval, so an agent onboards with no human involved. The client side gives three tools: `register`, `jmap_request` and `help`. Bundled presets cover common operations such as `send_mail`, `list_inbox` and `reply`. A custom domain is connected once in the dashboard, after which the inbox signs in with an API key or OAuth.
Who it is for. Agent developers who need their own mailbox for newsletters, support and surveys with no manual mail server setup.
Good fit when
- An agent subscribes to newsletters and sends a daily digest on AI tooling.
- A support inbox answers requests from the documentation and hands hard cases to a human.
- An agent runs an email survey and summarises the answers.
- Mail goes out from the company's own domain after the records are verified in the dashboard.
Not a fit when
- You need a mailbox with owner identity checks, while registration runs with no humans.
- Mail would be written on behalf of a specific person without their consent.
- Storage inside your own perimeter is required, while the mailbox lives in the Atomic Mail service.
Example request
Create an inbox named myagent, subscribe to three AI tooling newsletters and send me a daily digest.MCP
- Transport
- stdio
- Authentication
- key is optional
Environment variables
ATOMIC_MAIL_API_KEYsecret- An existing API key that skips proof of work registration.
ATOMIC_MAIL_CREDENTIALS_DIR- Credentials directory, defaults to `~/.atomicmail/`.
Limitations
The mailbox is created in the third-party Atomic Mail service, so mail and credentials are stored there. Free accounts have a 100 MB quota and limits sized for agents. The default `<name>@atomicmail.ai` address has no owner identity check, and sending from your own domain needs TXT and MX records verified in the dashboard. Credentials live in `~/.atomicmail/`, and `ATOMIC_MAIL_CREDENTIALS_DIR` changes the directory. Autonomous sending needs careful instructions for the agent so that it does not mail more than intended.
How to disable. Remove the atomicmail entry from the MCP configuration and the `~/.atomicmail/` directory with keys. The mailbox itself is closed in the Atomic Mail dashboard.
FAQ
How do I connect Atomic Mail to an agent?
Add an `atomicmail` entry to `mcpServers` with the command `npx` and the arguments `-y @atomicmail/mcp-github`, restart the client and ask it to create an inbox. There are also ClawHub and Hermes skills.
How does proof of work signup work?
The agent solves a computational task and gets an inbox in about 30 seconds with no CAPTCHA, domain or card. It is abuse protection with no manual approval.
Which tools are available?
`register` creates or signs in to an inbox, `jmap_request` runs JMAP requests or bundled presets and `help` returns built-in documentation and examples.
How do I send from my own domain?
Add the domain in the dashboard.atomicmail.ai panel, verify the TXT and MX records and create inboxes on it. Sign-in uses an API key through `atomicmail register --api-key` or OAuth.
Can it be used without MCP?
Yes. There is a skill, the console call `npx --package=@atomicmail/agent-skill-github atomicmail register` and a REST API for custom connectors.
Discussion
No questions or reviews yet.
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Comparison with similar tools
Cards that share the main search query, and how they differ.
| Tool | Official | Authentication | Repository stars | Main difference |
|---|---|---|---|---|
| Atomic Mail MCP (this card) | yes | key is optional | 256 | |
| email-mcp: an MCP server for IMAP and SMTP mail | no | key is optional | 158 | works with your mailboxes over IMAP and SMTP; Atomic Mail gives the agent its own inbox and signup with no human |
| MCP Agent Mail | no | API key | 2,235 | a mail layer for coordination between coding agents; Atomic Mail gives external email with an internet address |
README in short
The repository holds client integrations: MCP, a shell CLI, ClawHub and a Dify plugin. All of them rely on one auth, JMAP, presets and help stack.