# Thunderbird and AI: ChatGPT, Claude and MCP

> AI in Thunderbird: use ChatGPT, Claude and local models through add-ons, connect an agent over MCP, or forward a copy of your mail to Command Mail.

Updated: 2026-11-01 · Fact-checked: 2026-11-01 · Canonical: https://commandmail.app/en/guides/thunderbird-ai · Deutsch: https://commandmail.app/de/anleitungen/thunderbird-mit-ki-nutzen.md

The Thunderbird home page and the 159.0 release notes, retrieved on 2026-11-01, describe no built-in AI feature[^4][^6]. ChatGPT, Claude or a local model get into Thunderbird through add-ons such as ThunderAI or AI Mail Support[^10][^16]. If you want an agent to search your mailbox and write drafts on its own, you have two options: a local MCP server that drives the running Thunderbird[^21][^22], or a forwarded copy in an inbox built for agents.

Command Mail is our product and is the second of those options. We describe every option with its limits, because many people choose Thunderbird for local control, and an add-on with a local model may already be all they need[^4][^11].

## The short answer

1. To draft replies, summarize or translate single messages, install ThunderAI and set it up under Tools → Add-ons and Themes → ThunderAI → Preferences; with a free ChatGPT account you need no API key[^11][^13].
2. To keep message text away from cloud providers, point ThunderAI or AI Mail Support at Ollama or another local model[^11][^16].
3. To let Claude or Codex search your Thunderbird and write drafts, register a local MCP server, for example with `codex mcp add thunderbird -- node /path/to/thunderbird-mcp/mcp-bridge.cjs`; Thunderbird has to be running[^19][^21].
4. To let an agent work while your computer is off, forward mail from your provider to Command Mail and connect the agent there with narrow permissions[^1][^2].

## Which option fits which job?

The options differ in how much the AI sees, a single message or your whole mailbox, and in whether your computer has to stay on. The table draws on the project pages and help articles in the sources; we have not run any of these setups with a real account.

| Option | What the AI sees | Thunderbird must run | Sending | Who processes the content |
|---|---|---|---|---|
| ThunderAI | The message(s) or text you run it on; enabled automatic features process incoming mail[^11][^12] | Yes | The README documents no sending function of its own[^11] | The AI provider you pick, or your local model[^12] |
| AI Mail Support | The message or selected text you invoke it on[^16] | Yes | The listing documents no sending function of its own[^16] | The AI provider you pick, or your local model[^16] |
| AI Anywhere | What you enter in the chat window, or selected text you submit through a context-menu action[^17] | Yes | The listing describes no mailbox access[^17] | The chat website you pick[^17] |
| Thunderbird MCP | Every account you allow in Thunderbird[^21] | Yes[^21] | Compose uses a review window by default; direct sending only after disabling "Block skipReview"; automatic filter sending has a separate opt-in[^21] | Your assistant's model provider |
| thunderbird-cli | Every account in Thunderbird[^22] | Yes, plus a local bridge daemon[^23] | Drafts by default, sends only on an explicit call[^23] | Your assistant's model provider |
| Copy in Command Mail | The forwarded copies[^1] | No | From Pro, and only with your approval if you want[^2] | FYN Labs LLC, Cloudflare, TypeSafe for parts of the mail data, and your agent's model provider[^3] |

## Does Thunderbird have built-in AI?

Not in the sources retrieved on 2026-11-01. The current release is Thunderbird 159.0 and the extended support release is ESR 153.6.0[^5]. The 159.0 release notes mention no AI feature[^6], and the home page says Thunderbird does not secretly train AI with your private conversations[^4].

In April 2025 the Thunderbird team announced Thunderbird Assist, an experiment with AI features built with Flower AI[^7]. The plan was to run models on the device where possible, and the post said such features would always be optional and opt-in[^7]. Today the Thunderbird Pro page lists Thundermail, Appointment and Send, and the services roadmap we retrieved does not mention Assist[^8][^9]. These sources do not say whether or when it will ship.

## AI add-ons for Thunderbird

We looked at three add-ons from addons.thunderbird.net. The user counts are the daily averages the directory reports; they show reach, not quality.

**ThunderAI** (GPL-3.0, version 5.0.4.0 from 2026-10-03, Thunderbird 140 or later, about 19,300 daily users per the directory) works inside your mailbox[^10][^11]. It drafts replies, proofreads with an accept-or-reject view per change, rewrites in a polite or formal tone, summarizes one or more messages, translates, tags and classifies by your own criteria[^11]. With the companion add-on ThunderAI Sparks it turns a message into a calendar event or a task[^11]; the directory lists Sparks for Thunderbird 140 to 159[^15].

ThunderAI talks to ChatGPT through the website, to the OpenAI, Google Gemini and Claude APIs, to Ollama, or to any OpenAI-compatible server such as LM Studio[^11]. It has ready-made settings for DeepSeek, Grok, Mistral, OpenRouter and Perplexity[^11]. Administrators can preset or lock settings, connections and prompts through Thunderbird's enterprise policies[^11].

**AI Mail Support** (MIT, version 1.0.5 from 2026-09-29, Thunderbird 128 or later, about 940 daily users) offers AI actions in the message view, the compose window and on selected text[^16]. It supports Claude, DeepSeek, Gemini, GPT, Grok and Mistral, plus Groq Cloud and OpenRouter, and runs locally with LM Studio, Ollama or vLLM[^16]. Cloud providers need an account with an API key; usage charges depend on the plan, and the listing names free plans from Groq Cloud and Mistral AI with low request limits[^16].

**AI Anywhere for ChatGPT** (version 6.0 from 2026-10-27, license "All Rights Reserved", about 4,600 daily users) opens ChatGPT, Claude, Gemini, Grok, Mistral, Perplexity and other chat sites in a window with Alt+I[^17]. Its context menu summarizes, explains or translates selected text[^17]. The listing does not describe any access to your mailbox[^17].

## Set up ChatGPT in Thunderbird

The quickest route to ChatGPT is ThunderAI's ChatGPT Web Interface integration. It needs no API key, and a free ChatGPT account is enough, because the add-on drives the ChatGPT website on your behalf[^13].

1. Install ThunderAI from addons.thunderbird.net[^11]. On first run a setup wizard walks you through choosing a provider and testing the connection[^11].
2. Without the wizard, open Tools → Add-ons and Themes → ThunderAI → Preferences and choose "ChatGPT Web Interface" under Connection Type[^13].
3. Click the ThunderAI toolbar button. While the permission for chatgpt.com is missing, the popup shows a notice. Clicking it opens the welcome page; click the same notice at the top of that page, then accept Thunderbird's permission request[^13].
4. On your first prompt ThunderAI opens a ChatGPT window. Sign in there once; Thunderbird keeps the session[^13].
5. Open a message, click the ThunderAI button and pick a prompt such as Summarize. The answer appears in the ChatGPT window[^13].

The developer lists the trade-offs himself. The web integration is slower than the API, free accounts hit ChatGPT's own limits, and a layout change on the ChatGPT site can break it until ThunderAI is updated[^13]. Add Tags, Spam Filter, Summarize, Translate, Calendar Event and Task as settings-page features need an API integration; your toolbar prompts keep working through ChatGPT Web[^13].

ChatGPT does not connect to a local Thunderbird MCP server directly. OpenAI connects MCP servers at a public HTTPS address and points to Secure MCP Tunnel for servers on your own machine[^18]. Full MCP support with write actions is for Business, Enterprise and Edu; Pro users can connect custom servers with read and fetch permissions only[^18]. Codex starts local STDIO servers itself; you add one with `codex mcp add`[^19].

## Connect Claude to Thunderbird

For work on single messages, connect ThunderAI to the Claude API. You need an Anthropic account with API access and a key from console.anthropic.com; ThunderAI's guide lists no free option and calls the billing pay-per-use[^14]. ThunderAI stores the key locally in Thunderbird and sends it only to Anthropic's servers[^14].

If Claude should search your mailbox, read folders and write drafts, you need a local MCP server. Claude Desktop installs local servers as extensions under Settings → Desktop app → "Manage" next to Extensions[^20]; the two Thunderbird projects below are added as an entry in the Claude Desktop or Claude Code configuration[^21][^23]. Either way, the message text the server returns goes to your assistant's model.

## Local MCP servers for Thunderbird

A local MCP server gives an assistant tools for your Thunderbird. According to the Thunderbird MCP README, Thunderbird has no official API for AI tools[^21], so both projects ship their own extension that runs inside Thunderbird[^21][^23]. We read the project documentation on 2026-11-01 and did not run either server. GitHub stars show attention, not active users or a security review.

**Thunderbird MCP by TKasperczyk** (MIT, 417 stars, last GitHub push 2026-10-23) exposes 49 tools for mail, drafts, filters, contacts and calendars[^21]. By default the extension runs an HTTP server bound to localhost with a session-scoped token, and a small Node bridge translates between MCP and that server[^21]. Persistent tokens and a "Listen on all interfaces" option are available; the latter exposes the server on your local network over unencrypted HTTP[^21]. For Claude Code you register `node /path/to/thunderbird-mcp/mcp-bridge.cjs` as the server command[^21].

By default, sending opens a compose window where you review the message and send it yourself. Direct sending only works after you turn off the "Block skipReview" setting in the add-on's options[^21]. That block covers the compose tools; automatic Forward/Reply filter actions have a separate permission, off by default[^21]. The same options page controls which accounts and tools the server exposes, and an MCP client cannot change those settings[^21]. Encrypted messages stay withheld unless you explicitly allow them[^21].

You install `thunderbird-mcp.xpi` from the repository with Install from File[^21]; the public search on addons.thunderbird.net did not show it[^24]. The add-on uses Thunderbird's Experiment APIs. If Thunderbird disables it for that reason, the README recommends the ESR and names 140.16.0esr and 153.3.1esr as verified[^21]. Its auto-updates, the README notes, depend on continued control of the repository and its update domain[^21].

**thunderbird-cli by vitalio-sh** (MIT, 66 stars, created April 2026, last push 2026-11-01) offers 38 command-line commands and 12 MCP tools[^22][^23]. It needs three running parts: Thunderbird 128 or later, its extension, and a bridge daemon on 127.0.0.1:7700[^23]. Credentials stay in Thunderbird[^22].

Compose, reply and forward save drafts by default; the client must pass `mode: "send"` to send, and permanent deletion needs `confirm: true`[^23]. The README does not describe a switch that blocks sending for the assistant altogether. It says the extension is signed and approved on addons.thunderbird.net; you download it from the GitHub releases[^22].

Both servers only work while Thunderbird is running[^21][^23]. For the general difference between local and hosted servers, see [IMAP MCP or hosted MCP](https://commandmail.app/en/learn/imap-mcp-vs-hosted-mcp); more servers are compared in [best email MCP servers](https://commandmail.app/en/compare/best-email-mcp-servers). Anyone giving a model tools over email should also read [prompt injection in email](https://commandmail.app/en/learn/email-prompt-injection).

## The copy route: forward from your provider to Command Mail

Thunderbird is a mail client, and your mail lives with a provider such as Gmail, Outlook.com, Fastmail or your own domain's host. That is where you set up forwarding to Command Mail[^1]. You keep reading and writing in Thunderbird.

Command Mail receives copies of new messages. What the agent files or deletes there does not sync back to your original mailbox, so Thunderbird never sees it[^1]. Command Mail adds another operator: FYN Labs LLC in the United States, with the app and database on Cloudflare and attachments in Cloudflare's EU region[^3]. Parts of incoming mail go to the service provider TypeSafe to assess spam and phishing[^3]; the details are in [privacy of AI email assistants](https://commandmail.app/en/learn/ai-email-assistant-privacy).

## What you need for the copy

You need a Command Mail account. Free covers one mailbox with the last 90 days, including reading, search, sorting suggestions from the agent and drafts, but no sending[^2]. Direct sorting actions need the `auto` autonomy level, which according to the app code is not tied to a paid plan. Pro adds sending and up to ten mailboxes; the plan overview lists €19 a month for the first 100 paying Pro accounts while their subscription runs, and €29 after that[^2].

You also need access to your provider's web settings to switch on forwarding. To send from your own address through Command Mail, you need your provider's outgoing server and a sending password, which for many providers is an app password. You connect your agent, such as Claude, ChatGPT or Codex, at the end.

## Set up the copy

1. In Command Mail, add the address under "Connect a mailbox" in Settings → Connections, or from the CLI with `commandmail mailboxes connect you@example.com`. Command Mail then shows the private inbound address for it[^1].
2. At your provider, forward to that private inbound address. For Gmail and Outlook the steps are in [all your email addresses in one inbox](https://commandmail.app/en/guides/all-addresses-one-inbox).
3. Keep a copy at your provider. If it deletes forwarded mail, Thunderbird no longer shows it, because Command Mail does not sync anything back[^1].
4. For your own domain, confirm ownership with a TXT record, as described in [connect your own domain](https://commandmail.app/en/guides/connect-your-own-domain)[^1].
5. Connect the agent, for example in Claude Code with `claude mcp add --transport http commandmail https://commandmail.app/mcp`, and grant only `mail:read` and `mail:draft` when you sign in[^2].

If you have several accounts in Thunderbird, repeat the steps for each address; every address gets its own private inbound address[^1]. Older mail comes in through import, which does not set up ongoing sync[^1].

## Send from your own address through Command Mail

Receiving and sending are set up separately; from Pro, you add sending per sender address under Settings → Connections[^1]. According to the app code, Command Mail presets the outgoing server for Gmail, GMX, WEB.DE, iCloud, Yahoo, T-Online, Posteo and mailbox.org. You check the suggested user name and add the right password: an app password for Gmail, iCloud and Yahoo, T-Online's separate email password from its customer center, and for GMX and WEB.DE your account password, or an app password with two-factor sign-in, after switching on sending through external programs there. The app shows a note for each provider. For other providers, enter the server and password from your provider's help pages; Thunderbird's account settings already show that outgoing server.

Outlook.com and Hotmail are the exception: Microsoft only lets them send after an OAuth sign-in, so according to the app code these addresses use the relay. With the relay you confirm your address with a code, recipients see a Command Mail address with your name, and replies go to your own address. According to the app code, only a person in the app can set up a sending route, never an agent.

## Agent permissions: start small

`mail:read` and `mail:draft` are enough to begin. The agent reads, searches, sorts within the mailbox's autonomy level and writes drafts that are never sent[^2]. `mail:send-approved` may send exactly the draft revision you approved, provided the sending mailbox is not set to `read` and the plan and sending route allow it, and `mail:send` allows sending without approval only from mailboxes set to `auto`[^2].

`mail:read` covers every mailbox in your account. The autonomy level per mailbox controls what the agent may change there, and it does not separate access. New mailboxes start on `suggest`, or on `read` if the account default is `read`; see [permissions and autonomy](https://commandmail.app/en/docs/permissions-and-autonomy). In ChatGPT, Command Mail is a plugin, and in Claude a community connector in the directory; whether you can use plugins depends on plan, workspace, role and region, according to Command Mail[^2].

## Did it work?

For ThunderAI, open a message, choose a prompt such as Summarize from the toolbar, and check the answer in the chat or result window[^13]. For an MCP server, ask the assistant for your latest messages; it should name subjects and senders from Thunderbird. A test draft should show up in your Drafts folder without being sent[^21][^23].

For the copy, send a test message to your address from another account. It should arrive in Thunderbird and, shortly after, in Command Mail, and your agent should name it when asked[^1]. To check sending, reply to the test address and look at the sender there.

## Problems and fixes

**ThunderAI says you are not signed in.** Sign in inside the ChatGPT window, close it and run the prompt again. If signing in there fails, use the Open ChatGPT Tab button in ThunderAI's settings and sign in in that tab[^13].

**Auto-tagging or the spam filter does nothing.** These features need an API integration and do not run on ChatGPT Web. You can keep ChatGPT Web as the main connection and give each feature its own API connection[^13].

**Ollama does not answer ThunderAI.** The Ollama server must accept requests from the extension; set `OLLAMA_ORIGINS` to `moz-extension://*`[^11].

**The MCP server reports "Connection refused".** Thunderbird must be running with the extension enabled. Thunderbird MCP shows its port and status in the add-on's options[^21].

**Full-text search returns nothing on IMAP.** Thunderbird only indexes message bodies for folders synced for offline use; otherwise `searchBody` only searches headers[^21].

**Thunderbird disabled Thunderbird MCP.** The Experiment APIs may be the reason. Check Tools → Add-ons and Themes to see whether the add-on is enabled, and switch to the ESR if needed[^21].

**New mail does not reach Command Mail.** Check at your provider that forwarding is on and points to the right private inbound address[^1].

## Next steps

Start with the smallest option that solves your problem. An add-on covers replies and summaries, and with Ollama it needs no cloud provider at all. If an agent gets your whole mailbox, give it read and draft permissions only for the first week, and allow sending once you know how it works.

[Start Command Mail for free](https://commandmail.app/login?signup=1), forward one address from your provider and connect your agent.

## Sources and date

As of 2026-11-01. The pages from Thunderbird, Mozilla, the add-on developers, Anthropic and Command Mail, and the data from addons.thunderbird.net and GitHub, were retrieved that day; OpenAI's help article on custom MCP servers was retrieved on 2026-10-31. Statements about preset outgoing servers, Outlook.com and Hotmail, the relay, and that only a person can set up a sending route also rest on the app code at commit `ae32456` (`src/lib/mail/smtp-presets.ts`, `send-routes.ts`, `api/addresses/[id]/sending`). This guide does not claim a run-through with real accounts[^5][^21].

## Frequently asked questions

### Does Thunderbird have built-in AI?

The pages we checked on 2026-11-01 describe none: the home page and the Thunderbird 159.0 release notes list no built-in AI feature. In 2025 Thunderbird announced an optional experiment called Thunderbird Assist, but today's Thunderbird Pro page and its services roadmap do not mention it. For now, AI comes into Thunderbird through add-ons or local MCP servers.

### Do I need an API key to use ChatGPT in Thunderbird?

Not with ThunderAI's ChatGPT Web Interface integration, which also works with a free ChatGPT account by driving the ChatGPT website for you. The automatic features, such as auto-tagging, the spam filter and summarizing on arrival, need an API integration.

### Can Claude read my email in Thunderbird?

Yes, through a local MCP server such as Thunderbird MCP or thunderbird-cli in Claude Desktop or Claude Code. Both work through an extension inside the running Thunderbird. For working on single messages, ThunderAI with a Claude API key is enough.

### Can ChatGPT use a local Thunderbird MCP server?

Not directly. OpenAI says ChatGPT connects to remote MCP servers at a public HTTPS address and points to Secure MCP Tunnel for servers on your own machine. Full MCP support with write actions is limited to Business, Enterprise and Edu. Codex, by contrast, starts local STDIO servers itself.

### Does Thunderbird have to be running for an agent to work on my email?

For the add-ons and the local MCP servers, yes, because they work inside Thunderbird on your computer. If your provider forwards your mail to Command Mail, the agent works on the copy there, even when your computer is off.

## Sources

1. [Command Mail: Documentation, forwarding, sending and agents](https://commandmail.app/en/docs), accessed 2026-11-01
2. [Command Mail: plans and agent permissions](https://commandmail.app/llms.txt), accessed 2026-11-01
3. [Command Mail: Privacy policy](https://commandmail.app/privacy), accessed 2026-11-01
4. [Thunderbird: home page (donation-funded, no secret AI training)](https://www.thunderbird.net/en-US/), accessed 2026-11-01
5. [Mozilla: current Thunderbird versions (159.0, ESR 153.6.0esr)](https://product-details.mozilla.org/1.0/thunderbird_versions.json), accessed 2026-11-01
6. [Thunderbird 159.0 release notes](https://www.thunderbird.net/en-US/thunderbird/159.0/releasenotes/), accessed 2026-11-01
7. [Thunderbird Blog: Thundermail and Thunderbird Pro Services (April 2025, Thunderbird Assist)](https://blog.thunderbird.net/2025/04/thundermail-and-thunderbird-pro-services/), accessed 2026-11-01
8. [Thunderbird Pro: Thundermail, Appointment and Send](https://tb.pro/), accessed 2026-11-01
9. [Thunderbird: services roadmap](https://roadmaps.thunderbird.net/services/), accessed 2026-11-01
10. [addons.thunderbird.net: ThunderAI (version, license, users, compatibility)](https://addons.thunderbird.net/api/v4/addons/addon/thunderai/), accessed 2026-11-01
11. [ThunderAI: README and repository](https://github.com/micz/ThunderAI), accessed 2026-11-01
12. [ThunderAI: privacy per integration](https://micz.it/thunderbird-addon-thunderai/privacy/), accessed 2026-11-01
13. [ThunderAI: ChatGPT Web Interface setup guide](https://micz.it/thunderbird-addon-thunderai/guides/chatgpt-web/), accessed 2026-11-01
14. [ThunderAI: Claude API setup guide](https://micz.it/thunderbird-addon-thunderai/guides/claude-api/), accessed 2026-11-01
15. [addons.thunderbird.net: ThunderAI Sparks (compatibility)](https://addons.thunderbird.net/api/v4/addons/addon/thunderai-sparks/), accessed 2026-11-01
16. [addons.thunderbird.net: AI Mail Support](https://addons.thunderbird.net/api/v4/addons/addon/ai-mail-support/), accessed 2026-11-01
17. [addons.thunderbird.net: AI Anywhere for ChatGPT](https://addons.thunderbird.net/api/v4/addons/addon/ai_anywhere/), accessed 2026-11-01
18. [OpenAI Help: Connecting custom MCP servers in ChatGPT](https://help.openai.com/en/articles/12584461-connecting-custom-mcp-servers-in-chatgpt), accessed 2026-10-31
19. [OpenAI: Model Context Protocol in Codex (STDIO servers)](https://developers.openai.com/codex/mcp), accessed 2026-11-01
20. [Claude Help: Getting started with local MCP servers on Claude Desktop](https://support.claude.com/en/articles/10949351-getting-started-with-local-mcp-servers-on-claude-desktop), accessed 2026-11-01
21. [Thunderbird MCP (TKasperczyk): README and repository](https://github.com/TKasperczyk/thunderbird-mcp), accessed 2026-11-01
22. [thunderbird-cli (vitalio-sh): README and repository](https://github.com/vitalio-sh/thunderbird-cli), accessed 2026-11-01
23. [thunderbird-cli: MCP server README](https://github.com/vitalio-sh/thunderbird-cli/blob/main/mcp/README.md), accessed 2026-11-01
24. [addons.thunderbird.net: public search for "mcp"](https://addons.thunderbird.net/api/v4/addons/search/?q=mcp&app=thunderbird), accessed 2026-11-01

[^1]: [Command Mail: Documentation, forwarding, sending and agents](https://commandmail.app/en/docs), accessed 2026-11-01
[^2]: [Command Mail: plans and agent permissions](https://commandmail.app/llms.txt), accessed 2026-11-01
[^3]: [Command Mail: Privacy policy](https://commandmail.app/privacy), accessed 2026-11-01
[^4]: [Thunderbird: home page (donation-funded, no secret AI training)](https://www.thunderbird.net/en-US/), accessed 2026-11-01
[^5]: [Mozilla: current Thunderbird versions (159.0, ESR 153.6.0esr)](https://product-details.mozilla.org/1.0/thunderbird_versions.json), accessed 2026-11-01
[^6]: [Thunderbird 159.0 release notes](https://www.thunderbird.net/en-US/thunderbird/159.0/releasenotes/), accessed 2026-11-01
[^7]: [Thunderbird Blog: Thundermail and Thunderbird Pro Services (April 2025, Thunderbird Assist)](https://blog.thunderbird.net/2025/04/thundermail-and-thunderbird-pro-services/), accessed 2026-11-01
[^8]: [Thunderbird Pro: Thundermail, Appointment and Send](https://tb.pro/), accessed 2026-11-01
[^9]: [Thunderbird: services roadmap](https://roadmaps.thunderbird.net/services/), accessed 2026-11-01
[^10]: [addons.thunderbird.net: ThunderAI (version, license, users, compatibility)](https://addons.thunderbird.net/api/v4/addons/addon/thunderai/), accessed 2026-11-01
[^11]: [ThunderAI: README and repository](https://github.com/micz/ThunderAI), accessed 2026-11-01
[^12]: [ThunderAI: privacy per integration](https://micz.it/thunderbird-addon-thunderai/privacy/), accessed 2026-11-01
[^13]: [ThunderAI: ChatGPT Web Interface setup guide](https://micz.it/thunderbird-addon-thunderai/guides/chatgpt-web/), accessed 2026-11-01
[^14]: [ThunderAI: Claude API setup guide](https://micz.it/thunderbird-addon-thunderai/guides/claude-api/), accessed 2026-11-01
[^15]: [addons.thunderbird.net: ThunderAI Sparks (compatibility)](https://addons.thunderbird.net/api/v4/addons/addon/thunderai-sparks/), accessed 2026-11-01
[^16]: [addons.thunderbird.net: AI Mail Support](https://addons.thunderbird.net/api/v4/addons/addon/ai-mail-support/), accessed 2026-11-01
[^17]: [addons.thunderbird.net: AI Anywhere for ChatGPT](https://addons.thunderbird.net/api/v4/addons/addon/ai_anywhere/), accessed 2026-11-01
[^18]: [OpenAI Help: Connecting custom MCP servers in ChatGPT](https://help.openai.com/en/articles/12584461-connecting-custom-mcp-servers-in-chatgpt), accessed 2026-10-31
[^19]: [OpenAI: Model Context Protocol in Codex (STDIO servers)](https://developers.openai.com/codex/mcp), accessed 2026-11-01
[^20]: [Claude Help: Getting started with local MCP servers on Claude Desktop](https://support.claude.com/en/articles/10949351-getting-started-with-local-mcp-servers-on-claude-desktop), accessed 2026-11-01
[^21]: [Thunderbird MCP (TKasperczyk): README and repository](https://github.com/TKasperczyk/thunderbird-mcp), accessed 2026-11-01
[^22]: [thunderbird-cli (vitalio-sh): README and repository](https://github.com/vitalio-sh/thunderbird-cli), accessed 2026-11-01
[^23]: [thunderbird-cli: MCP server README](https://github.com/vitalio-sh/thunderbird-cli/blob/main/mcp/README.md), accessed 2026-11-01
[^24]: [addons.thunderbird.net: public search for "mcp"](https://addons.thunderbird.net/api/v4/addons/search/?q=mcp&app=thunderbird), accessed 2026-11-01

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