mcp4mail

Name: mcp4mail
Author: jchsoft

作者：jchsoft版本 1.0.0i★ –i在云端运行

注册名称online.mcp4mail/mcp4mail

安装

概览

作者提供的说明（英文原文）

Your IMAP mailbox as an MCP server: read, search and (if you allow it) organize mail. Open source.

PopNx MCP 的三大支柱

这三项永远不会合并成一个分数：意见、测量和人气是不同的东西。

用户评价i暂无评价评价功能将在后续阶段与账户功能一起开放
我们的基础检查i3 项中通过 3 项依据公开信息检查；尚未扫描代码
使用情况i非常新★ –

它能帮你做什么

我们还没有为它写通俗的介绍。下面是我们从注册中心读取到的事实。

连接方式: 在云端运行
传输方式: Streamable HTTP
分类: 搜索与 AI 记忆

安装

选择你使用的 AI 应用，然后复制设置。

安装之前

基础检查：3 项中通过 3 项
在作者的服务器上运行：你向它提出的内容会经过他们的服务器。
注册中心没有列出需要填写的密钥。

你需要

在云端运行无需安装任何东西，通过互联网连接

你用的是哪个应用？

ClaudeClaude CodeCursorVS CodeChatGPT

在上方选择你的应用。我们会记住它，下次按钮会显示“安装到 …”。

适用于网页版、桌面版和手机版 Claude：

打开 Settings → Connectors
点击 Add custom connector
粘贴下面的地址，然后点击 Add
如果要求登录，请登录作者的服务

https://mcp4mail.online/mcp

在终端中运行这条命令

claude mcp add --transport http mcp4mail https://mcp4mail.online/mcp

在 Cursor 中打开

或者自己复制设置

粘贴到项目中的 .cursor/mcp.json，或 ~/.cursor/mcp.json

{
  "mcpServers": {
    "mcp4mail": {
      "url": "https://mcp4mail.online/mcp"
    }
  }
}

浏览器会先询问是否打开应用，然后应用会显示设置并请你确认。密钥的值会留空，由你自己填写。

在 VS Code 中打开

或者自己复制设置

粘贴到项目中的 .vscode/mcp.json

{
  "servers": {
    "mcp4mail": {
      "type": "http",
      "url": "https://mcp4mail.online/mcp"
    }
  }
}

浏览器会先询问是否打开应用，然后应用会显示设置并请你确认。密钥的值会留空，由你自己填写。

ChatGPT 只能连接互联网上的服务器：

打开网页版 ChatGPT → Settings → Connectors (Apps)
点击 Create 或 Add（部分套餐需要先在 Advanced 中开启 Developer mode）
粘贴下面的地址，起个名字，然后保存
如果要求登录，请登录作者的服务

https://mcp4mail.online/mcp

菜单名称可能因套餐和版本不同而略有差异。

你的选择通过 Cookie 保存在这台设备上，无需账户。

这些设置是根据作者在注册中心的条目生成的。如果 README 的写法不同，请以 README 为准。

它能做什么

服务器要求先登录，才会列出它的工具。

基础检查i

我们检查的是任何人都能看到的信息；我们没有阅读代码。不适用的检查项不计入总数。 · 检查于 2026年11月9日

✓ 通过
作者与仓库一致
注册名称已通过域名 mcp4mail.online 验证（注册中心会核实域名所有权）
… 尚未检查
仍在维护
我们还没有从 GitHub 读取这个仓库
… 尚未检查
有许可证
我们还没有从 GitHub 读取这个仓库
✓ 通过
端点有响应
在 741 毫秒内响应（HTTP 401）
✓ 通过
使用 OAuth 登录
声明支持 OAuth 登录，你的 AI 应用可以带你去登录
… 尚未检查
工具描述中没有隐藏指令
尚未检查；我们会在检查端点时读取工具列表

与“搜索与 AI 记忆”中的其他服务器比较i

星标数多于此分类中其他 5765 个服务器的 0%
发布到注册中心的时间比此分类中其他 5765 个服务器的 49% 更新
基础检查结果等于或优于此分类中其他 5765 个服务器的 100%

与注册中心里这个分类中所有活跃的服务器比较。只有当发布者拥有该仓库时，星标数才计入。

常见问题

mcp4mail 安全吗？

它在 3 项适用的基础检查中通过了 3 项。我们没有阅读代码。在添加密钥或令牌之前，请先看看这个服务器要求哪些权限，并使用只具备所需权限的密钥。

它需要哪些密钥或代码？

注册中心没有列出必需的密钥，不过有些服务器会在首次使用时要求你登录。

它在我的电脑上运行还是在云端？

它在作者的云端运行。通过互联网连接，无需安装，但你发送的内容会经过作者的服务器。

它还在维护吗？

GitHub 仓库最后更新于–，最新版本（1.0.0）于42天前进入注册中心。

哪些应用可以使用它？

支持 MCP 的应用，例如 Claude Desktop、Claude Code、Cursor 和 VS Code。它通过 URL 连接，所以接受远程 MCP 服务器的应用也可以使用，例如开启开发者模式的 ChatGPT。

有什么可以替代它？

同一分类中有：Context7, Codebase Memory, Exa

替代选择

同一分类中其他作者的服务器，按星标数排序。

如何看卡片：↓ 每周下载量i★ GitHub 星标i三大支柱：评价 · 检查 · 使用情况i更新 = 最新版本发布到注册中心的时间i

Context7

Up-to-date docs for AI agents

作者：upstash广泛使用↓ 97.3万/周★ 6.4万3天前更新

电脑或云端

安装

Codebase Memory

Codebase knowledge graph for AI agents — 162 languages, sub-ms queries, 99% fewer tokens.

作者：DeusData广泛使用↓ 1.8万/周★ 4.8万23天前更新

在你的电脑上运行

安装

Exa

Connect AI agents to Exa for web search, content fetching, and multi-step research.

作者：exa-labs广泛使用★ 52132个月前更新

在云端运行✓ exa.ai

安装

作者的 README

打开 README

按原文从作者的仓库复制。PopNx MCP 没有审查或背书其内容。HTML、图片和脚本已被移除。链接会离开本站。

mcp4mail

Your mailbox as an MCP server. Connect an IMAP account and let your AI assistant read and search your mail, authorized over OAuth 2.1. Hosted at mcp4mail.online, open source and self-hostable.

Run it yourself and your credentials never leave your machine. A hosted mail connector necessarily keeps your IMAP password on someone else's server; with mcp4mail you can keep it in your own database instead. One docker compose up gets you there: see the self-hosting guide.

mcp4mail is young, and we use it ourselves. Today it exposes the 14 tools listed below: list your accounts and folders, search headers, read messages, download attachments and look up contacts. It can also change a mailbox (flag, move, trash, create folders, save drafts, send), but only where the mailbox owner switched on "Allow the AI to make changes" and ticked that permission; every mailbox is read-only by default, and send_message only prepares an email that leaves after a human presses Send.

Try it

Hosted: go to mcp4mail.online, sign up, connect an IMAP account, and add https://mcp4mail.online/mcp to your MCP client.
Self-host: cp .env.example .env, fill it in, then docker compose up -d. See the self-hosting guide.

This project is primarily developed by AI developers orchestrated through mcptask.online. Watch the development happen live: https://mcptask.online/live

How this project is built

This is a real open-source product and, at the same time, a public demonstration. Tasks are written by people in mcptask.online, picked up by runners (Claude Code driven by the mcptask runner, on our own machines), and every change follows the same path: task → branch → pull request → tests & CI → merge → deploy to mcp4mail.online. Nobody, person or runner, pushes to main directly: the branch is protected by a repository ruleset that requires an open pull request, a linear history, and green status checks (security scans, lint, unit tests, system tests) before a squash merge is allowed.

Watch it live: https://mcptask.online/live

Where to look if you want to verify any of this yourself: the Pull requests tab, where each PR links its task and shows its CI runs, including the failed ones; CLAUDE.md and .claude/, the instructions the runners work from; and the CI configuration.

People still write the task briefs, review the pull requests, and decide what ships and what doesn't; a runner executes a task end to end, but it is not deciding what to build. A runner is a user with a seat here, not something free or unlimited.

MCP tools

Point your AI client at https://mcp4mail.online/mcp (or your own instance's /mcp URL) and sign in. Steps for Claude, Claude Code, ChatGPT, Cursor and VS Code: docs/mcp-clients.md.

Tool	What it does
`list_mail_accounts`	Lists the mail accounts you connected, with the ids the other tools take.
`get_mail_account`	Shows the connection details of one account (never its password).
`list_folders`	Lists the folders of one account.
`search_messages`	Searches by subject, sender, recipients, attachment names and date.
`get_message`	Reads one message.
`get_attachment`	Downloads an attachment of a message: a short-lived link, or with `inline: true` the file itself (up to 5 MB) inside the MCP answer.
`search_contacts`	Finds addresses you have corresponded with.
`get_outgoing_status`	Tells whether an email handed to `send_message` has gone out.
`set_flags`	Flags a message or marks it read / unread. Write.
`move_message`	Moves a message to another folder. Write.
`trash_message`	Moves a message to Trash. Write.
`create_folder`	Creates a folder. Write.
`create_draft`	Saves a draft. Write.
`send_message`	Prepares an email; it is sent only after you approve it. Write.

Write tools work only on a mailbox whose owner switched on "Allow the AI to make changes to this mailbox" and ticked what the tool does; everywhere else they are refused, see below. send_message never sends on its own: you get an email with a link and the message leaves only when you press Send.

Self-hosting

cp .env.example .env    # fill in the values

docker compose up -d

Read docs/self-hosting.md first: which environment variables matter, why HITCH_RESOURCE_URI must match your public URL exactly, TLS, and how mailbox passwords are stored.

Stack

Ruby 3.4, Rails 8.1, PostgreSQL, Hotwire (Turbo + Stimulus), Tailwind CSS, Solid Queue / Cache / Cable.

Development

bin/setup   # install gems, prepare the database, start the dev server

bin/dev # web server + Tailwind watcher bin/ci # rubocop, security audits, tests, system tests

PostgreSQL must be running locally; the default config connects over the local socket as your OS user.

Secrets

This repository is public. Nothing secret is ever committed: config/master.key, .env* and credentials.yml are git-ignored, production secrets come from the environment.

Mailbox passwords are encrypted at rest with Active Record Encryption. In production, generate keys with bin/rails db:encryption:init and provide them through the encrypted credentials (active_record_encryption.*) or the ACTIVE_RECORD_ENCRYPTION_PRIMARY_KEY, ACTIVE_RECORD_ENCRYPTION_DETERMINISTIC_KEY and ACTIVE_RECORD_ENCRYPTION_KEY_DERIVATION_SALT environment variables. Development and test derive throwaway keys from the per-machine tmp/local_secret.txt.

Mail accounts

mcp4mail connects to your mailbox over plain IMAP with a username and password. Use an app-specific password wherever your provider offers one (Gmail, iCloud, Fastmail, Outlook.com, Yahoo and others do), so that what is stored in the database can be revoked on its own and is not the key to your whole account. Gmail is supported the same way: turn on two-step verification and sign in with an app password. On a Google Workspace account the administrator can switch off IMAP or app passwords, and only they can turn them back on. How the password is stored and who can decrypt it is described in the security notes of the self-hosting guide.

MCP endpoint: read-only by design

Every mailbox is read-only until you say otherwise. Each mailbox on the Mail accounts page has one switch, "Allow the AI to make changes to this mailbox", and it is off by default.

Off (the default): the AI can only read and search. Any tool that would change the mailbox is refused with a message telling the model the mailbox is read-only, and the refusal is written to the audit log as denied.
On: checkboxes unfold under the switch and you tick what the AI may do in that mailbox: mark as read and flag (set_flags), move messages and create folders (move_message, create_folder), write drafts (create_draft), send and reply, always after your approval (send_message), delete to trash (trash_message). All are ticked when you switch it on. A tool whose box is unticked is refused the same way as on a read-only mailbox. list_mail_accounts and get_mail_account tell the model what it may do.

The tool registry refuses to boot with a tool that is neither read-only and non-destructive nor explicitly declared as a write tool (write_tool destructive: ..., permission: ... on McpTools::ApplicationTool, where permission is one of the checkboxes above), so nothing can slip in as a write tool by accident. Write tools announce readOnlyHint: false and declare their own destructiveHint.

What read-only does and does not mean, plainly:

Nothing can change a mailbox without its switch and the matching checkbox. Folders are opened with IMAP EXAMINE, so even reading does not mark messages as seen.
It does read your mail, whenever an AI client you connected asks. Connect only clients you trust with that.
It keeps a copy of message headers (sender, recipients, subject, date, flags, size) in its own database, refreshed every 15 minutes, so searches do not hit your mail server each time.

Scoping. Every tool resolves data through the signed-in user's own mail accounts; an account id that is not theirs is refused before any tool code runs.
Rate limits. Hitch limits each user + client pair (120 requests a minute); on top of that each user has one quota for tool calls across all their clients (240 a minute).
Audit log. Every call is written to mcp_audit_events: user, client, tool, account, outcome, rows returned, duration. Arguments are not stored.
Search guard. Pages are capped at 50 results, and each account has a budget of searches (60 per 10 minutes) and returned rows (1,000 an hour), so a runaway loop cannot walk a whole mailbox.

FAQ

Why IMAP and not the Gmail or Microsoft Graph API? The target user is on their own IMAP host, where there is no vendor API to call. Plain IMAP with a username and an app password works everywhere, so there is no Gmail or Microsoft OAuth. See Mail accounts.

Where is my mail password stored, and who can decrypt it? In PostgreSQL, encrypted with Active Record Encryption (AES-256-GCM). It is decrypted only in memory to open the IMAP connection, and never shown, returned by a tool or logged. Whoever holds the encryption keys can decrypt it; if you self-host, that is you.

Can the AI send or delete mail on its own? No. Every mailbox is read-only until its owner switches on "Allow the AI to make changes" and ticks what is allowed. Even then send_message only prepares an email that leaves after you press Send, and deleting means trash_message, which moves to Trash. See read-only by design.

Does it store my mail? Only message headers (sender, recipients, subject, date, flags, size), refreshed every 15 minutes so searches do not hit your mail server each time. Message bodies are read from your mail server when the AI asks for one.

Does it work with Outlook, Exchange or Gmail? Where the provider offers IMAP with an app password, yes: Gmail, iCloud, Fastmail, Outlook.com and Yahoo do. Whether an Exchange server allows IMAP is up to its administrator. See Mail accounts.

Is it free? Yes. It is MIT-licensed and self-hostable, and the hosted service at mcp4mail.online is run from the same code.

Contributing

See CONTRIBUTING.md. bin/ci must pass.

License

MIT

mcp4mail

概览

PopNx MCP 的三大支柱

它能帮你做什么

安装

安装之前

它能做什么

基础检查i

作者与仓库一致

仍在维护

有许可证

端点有响应

使用 OAuth 登录

工具描述中没有隐藏指令

与“搜索与 AI 记忆”中的其他服务器比较i

常见问题

替代选择

Context7

Codebase Memory

Exa

作者的 README

mcp4mail

Try it

How this project is built

MCP tools

Self-hosting

Stack

Development

Secrets

Mail accounts

MCP endpoint: read-only by design

FAQ

Contributing

License