JMAP mail

Name: JMAP mail
Author: kOlapsis

by kOlapsisversion 0.3.0i★ –iRuns on your computer

Registry nameio.github.kOlapsis/jmap-mcp

Install

Overview

Description from the maker (original English)

Read, organize, draft and send email on any JMAP server, with OAuth sign-in and zero configuration

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Chat & email

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
You fill in yourself: JMAP_MCP_ENABLE_SEND, JMAP_MCP_LOG_LEVEL

You need

DockerDocker installed

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Download the maker’s .mcpb file

The link goes to the maker’s own file; we do not host or repackage it. Open the file and Claude Desktop installs it.

Run this in your terminal

claude mcp add jmap --env JMAP_MCP_ENABLE_SEND=your-value --env JMAP_MCP_LOG_LEVEL=your-value -- docker run -i --rm -e JMAP_MCP_ENABLE_SEND -e JMAP_MCP_LOG_LEVEL ghcr.io/kolapsis/jmap-mcp:0.3.0 stdio

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "jmap": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e",
        "JMAP_MCP_ENABLE_SEND",
        "-e",
        "JMAP_MCP_LOG_LEVEL",
        "ghcr.io/kolapsis/jmap-mcp:0.3.0",
        "stdio"
      ],
      "env": {
        "JMAP_MCP_ENABLE_SEND": "your-value",
        "JMAP_MCP_LOG_LEVEL": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "jmap": {
      "type": "stdio",
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e",
        "JMAP_MCP_ENABLE_SEND",
        "-e",
        "JMAP_MCP_LOG_LEVEL",
        "ghcr.io/kolapsis/jmap-mcp:0.3.0",
        "stdio"
      ],
      "env": {
        "JMAP_MCP_ENABLE_SEND": "your-value",
        "JMAP_MCP_LOG_LEVEL": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

JMAP_MCP_ENABLE_SEND env
Allow sending email; every message is still confirmed by the user
JMAP_MCP_LOG_LEVEL env
Log level

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account kOlapsis, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Chat & emaili

More stars than 0% of the other 1774 servers in this category
Published to the registry more recently than 68% of the other 1774 servers in this category
Basic checks equal to or better than 100% of the other 1774 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is JMAP mail safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.3.0) reached the registry 13 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Docker, MCPB on your computer.

What can I use instead?

In the same category: Vexa, emailmd, MCP WhatsApp Cloud

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Vexa

by Vexa-ai

Meeting bot and transcripts for Google Meet, Teams and Zoom. Live or after, speakers labelled.

Runs in the cloud★ 2,949Apache-2.0Updated 2 months ago

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emailmd

by anypost

Render markdown into email-safe HTML, lint drafts for deliverability problems, and preview emails.

Computer or cloud★ 1,385MITUpdated 31 days ago

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MCP WhatsApp Cloud

by codespar

MCP server for WhatsApp Cloud API (Meta) — messages, media, and templates via Graph API

Runs on your computer★ 277MITUpdated 5 months ago

Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

jmap-mcp

An MCP server that gives an AI assistant (Claude.ai, Claude Code, Claude Desktop or any MCP client) access to a mailbox hosted on a JMAP server (RFC 8620, RFC 8621), first of all Stalwart.

The user gives an email address and signs in on their mail server's own page. Nothing else is configured: no server URL, no token, no API key.

Why

Sovereignty. Your mail stays on your server. The bridge is self-hosted, stores no email, and keeps only encrypted OAuth tokens.
Zero configuration. The JMAP server is found from the email address (DNS SRV, then /.well-known/jmap), its OAuth server from standard metadata, and the bridge registers itself dynamically. Secrets are generated on first start.
Clean OAuth, no token passthrough. MCP clients get tokens issued by the bridge for the bridge; mail-server tokens never leave it, as the MCP authorization spec requires. It works as a Claude.ai custom connector with the Client ID left empty.
Any JMAP server. Nothing is Stalwart-specific: any server with JMAP and an OAuth server supporting RFC 8414 metadata and RFC 7591 dynamic registration works.

Existing JMAP MCP servers (mikluko/jmap-mcp, wyattjoh/jmap-mcp, agent-jmap-mcp, fastmail-blade-mcp) all need a server URL and a static token in their configuration, and none can be added to Claude.ai as a connector.

Tools

A small surface designed for an agent: compact JSON results, pagination everywhere, bodies converted to text and truncated with an explicit flag.

Tool	What it does
`list_accounts`	Connected accounts and the default one (`set_default` changes it).
`connect_account`	Local mode only: connect an account from an email address (browser or device code).
`list_mailboxes`	Mailboxes with role (inbox, sent, drafts, trash, archive, junk), path, total and unread counts.
`list_identities`	Sender identities. Registered when the server announces submission.
`search_emails`	Text, sender, recipient, subject, mailbox, dates, unread, flagged, attachments, size; sort; position and limit. Returns summaries.
`get_email`	Headers, plain-text body (HTML converted when there is no text part), attachment list. `max_body_length`.
`get_thread`	A conversation in order, as summaries or full messages.
`get_attachment`	Text and small images inline; otherwise a signed URL valid 15 minutes (HTTP mode) or a private temporary file (local mode).
`update_emails`	Read, unread, flagged, unflagged.
`move_emails`	Move to a mailbox given by id, role or name.
`create_folder`	Create a folder, at the top level or inside a parent given by id, role or name.
`delete_emails`	Trash by default; `permanent` destroys after the user's confirmation.
`create_draft`	New message or reply: In-Reply-To, References, `Re:` subject, quote, reply-all recipients, attachments uploaded over JMAP.
`send_email`	Sends a draft, or composes and sends. Disabled unless `--enable-send`; every message is confirmed by the user.
`vacation_response`	Read or change the out-of-office reply (changes are confirmed). Registered when the server announces it.
`sieve_scripts`	List, read, write, activate, deactivate, delete filtering rules (RFC 9661); changes are confirmed. Registered when announced.

The resource jmap-mcp://status describes the connected accounts, the discovered servers and the capabilities they announce.

Email content is treated as untrusted data: it is returned to the model as data, never interpreted, and the tool descriptions tell the model that emails may contain instructions it must ignore.

Choices that are not secret (which account, which sender identity, confirmation of a send or a permanent deletion) are asked through MCP elicitation when the client supports it. Otherwise the tool returns an error listing the choices, and the model calls it again with the argument set (account, identity, confirm). Credentials never go through elicitation or tool arguments.

How it works

                         HTTP mode                                     mail server

┌──────────────┐ OAuth 2.1 (bridge tokens) ┌──────────────┐ OAuth (mail tokens) ┌──────────────┐ │ MCP client │ ──────────────────────────▶ │ jmap-mcp │ ────────────────────▶ │ OAuth server │ │ Claude.ai… │ ◀── MCP over HTTP ────────▶ │ (bridge) │ ◀──── JMAP ─────────▶ │ JMAP API │ └──────────────┘ └──────────────┘ └──────────────┘

In HTTP mode (jmap-mcp serve) the bridge is at the same time:

a protected resource (RFC 9728 metadata, 401 with WWW-Authenticate, audience checked on every request);
a minimal authorization server for MCP clients (RFC 8414 metadata, PKCE S256, RFC 8707 resource indicators, RFC 7591 dynamic registration, Client ID Metadata Documents, rotating refresh tokens);
an OAuth client of the mail server: its sign-in page asks for the email address, discovers the server, registers itself there once per server, and redirects the user to the mail server's authorization code flow with PKCE. Only after the mail server returns does the bridge issue its own code and tokens.

A single deployment serves users of different mail servers. Each user gets an isolated MCP server instance and can only reach their own accounts.

In local mode (jmap-mcp, stdio) there is no third party: the process is the OAuth client of the mail server, like a mail application. It registers as a public client, opens the browser on a loopback redirect, and falls back to the device flow (RFC 8628) when no browser can be opened, showing the code to type.

Installation

1. Docker behind Traefik

The image is ghcr.io/kolapsis/jmap-mcp (linux/amd64 and linux/arm64, distroless, non-root, data in the /data volume). With a Traefik that already has a websecure entrypoint and an ACME resolver, copy docker-compose.yml, set your host name, resolver and network, and start it:

curl -O https://raw.githubusercontent.com/kOlapsis/jmap-mcp/main/docker-compose.yml

edit mcp.example.com, the certresolver name and the network

docker compose up -d curl https://mcp.example.com/healthz

Traefik sets the X-Forwarded-* headers from which the bridge derives its public URL. Set JMAP_MCP_PUBLIC_URL only if your proxy does not send them.

Image tags: X.Y.Z, X.Y, X and latest for releases, main and sha- for the latest build of the main branch. Both are built by GitHub Actions and pushed to ghcr.io.

Without Traefik, deploy/caddy has a Caddy setup that obtains the certificate itself:

cd deploy/caddy   # edit mcp.example.com in the Caddyfile

docker compose up -d

The MCP address is https://mcp.example.com/mcp.

2. Add it to Claude.ai

Settings › Connectors › Add custom connector. Give it a name and the URL https://mcp.example.com/mcp. Leave Client ID and Client Secret empty in the advanced settings: Claude.ai registers itself dynamically (its redirect URI is https://claude.ai/api/mcp/auth_callback). Click Connect, enter your email address on the bridge page, then sign in on your mail server.

The free plan is limited to one custom connector. On Team and Enterprise plans, an owner adds the connector under Organization settings › Connectors.

3. Claude Code with the remote bridge

claude mcp add --transport http mail https://mcp.example.com/mcp

Then run /mcp in Claude Code and choose the server to authenticate in the browser.

4. Claude Code and Claude Desktop, local (stdio)

Install the binary, from the releases, with Homebrew (brew install --cask kolapsis/tap/jmap-mcp, macOS and Linux) or with Go:

go install github.com/kOlapsis/jmap-mcp@latest

Claude Code:

claude mcp add mail -- jmap-mcp

or in .mcp.json:

"mcpServers": { "mail": { "command": "jmap-mcp", "args": ["stdio"] } } }

Claude Desktop: install jmap-mcp.mcpb from the release (double-click it, or Settings › Extensions), or add to claude_desktop_config.json the full path of the binary:

"mcpServers": { "mail": { "command": "/usr/local/bin/jmap-mcp", "args": ["stdio"] } } }

On first use, ask the assistant to connect your mailbox. It asks for your email address (elicitation, or the connect_account tool), opens your browser on the mail server's sign-in page, and the account is ready. Without a graphical session (SSH), it shows a URL and a code to enter on any device. Tokens are stored in the data directory (~/.config/jmap-mcp on Linux), encrypted with a key kept in the OS keyring, or in a 0600 key file when no keyring is available. Several accounts can be connected.

To send email in local mode, add "env": {"JMAP_MCP_ENABLE_SEND": "true"} to the server entry.

5. Binary with systemd

sudo install -m 755 jmap-mcp /usr/local/bin/

sudo cp deploy/systemd/jmap-mcp.service /etc/systemd/system/ sudo systemctl daemon-reload && sudo systemctl enable --now jmap-mcp

The unit listens on 127.0.0.1:8080 with a dynamic user and its state in /var/lib/jmap-mcp. Put a TLS reverse proxy in front of it (any proxy that sends X-Forwarded-Proto and X-Forwarded-Host), or set JMAP_MCP_PUBLIC_URL.

Preparing the mail server

Discovery. The JMAP server is found from the email domain, as RFC 8620 §2.2 describes: an SRV record _jmap._tcp.example.com pointing at the JMAP host, otherwise https://example.com/.well-known/jmap. If your web site is not served by the mail server, add the SRV record:

_jmap._tcp.example.com. 3600 IN SRV 0 1 443 mail.example.com.

The OAuth server is found from the JMAP host: RFC 9728 resource metadata, then RFC 8414 and OpenID Connect discovery. It must be under the same registrable domain as the JMAP host (for example jmap.example.com and auth.example.com); otherwise the bridge refuses the server.

Client registration with Stalwart. Nothing to do with the default settings: the bridge registers itself as a public client with PKCE, which Stalwart accepts anonymously (anonymousClientRegistration, on by default in Stalwart 0.16). Stalwart only issues confidential clients to authenticated callers, so the bridge does not get a client secret this way; PKCE protects the authorization code instead.

If the operator turned anonymous registration off, declare the client statically:

In Stalwart, Management › Directory › OAuth Clients, create a client with the redirect URI https://mcp.example.com/callback (and a secret if you want a confidential client).
Get the admin token of the bridge: docker compose exec jmap-mcp /jmap-mcp admin-token (or `jmap-mcp admin-token --d

Only the beginning is shown; read the rest in the repo

JMAP mail

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Chat & emaili

Common questions

Alternatives

Vexa

emailmd

MCP WhatsApp Cloud

README from the maker

jmap-mcp

Why

Tools

How it works

Installation

1. Docker behind Traefik

edit mcp.example.com, the certresolver name and the network

2. Add it to Claude.ai

3. Claude Code with the remote bridge

4. Claude Code and Claude Desktop, local (stdio)

5. Binary with systemd

Preparing the mail server