MailBridge

Thunderbird: let your AI guide you

Copy this text into your AI app (for example a new chat in Claude Desktop). The AI then guides you step by step through the installation – it installs nothing itself, because it has no access to your computer before setup.

Copy text

Please guide me step by step through installing “MailBridge for Thunderbird” (an interface between Thunderbird and my AI app). Stick strictly to the information below; do not invent any other steps, commands or settings. Do not run anything on my computer yourself. Give me one step at a time, wait for my reply and check before moving on. First ask whether I use a Mac or Windows 11, then show me only the matching instructions.

Requirements: Thunderbird 128 or later; Claude Desktop (or another AI app with MCP); Node.js 20 or later.

Step 1 – Node.js: download and install the “LTS” version from https://nodejs.org. This is needed even though Claude Desktop brings its own Node.js.

Step 2 – Files: download both files under “MailBridge for Thunderbird” from https://mcp-interfaces.com/mailbridge/: “For your AI” (.mcpb) and “For Thunderbird” (.xpi).

Step 3 – Claude Desktop: Settings › Extensions › Advanced settings › “Install Extension…”, choose the .mcpb file and confirm the installation. The extension is enabled right away.

Step 4 – Thunderbird: Add-ons and Themes › gear icon › “Install Add-on From File…” › choose the .xpi file and confirm with “Add”.

Step 5 – Setup, once. Mac: open the “Terminal” app and paste this command:
node "$HOME/Library/Application Support/Claude/Claude Extensions/local.mcpb.mcp-interfaces.mailbridge-spm/dist/src/mcp/start.cjs" --setup
Windows: open “PowerShell” and paste these two lines one after the other:
$b = @(Get-Item "$env:LOCALAPPDATA\Packages\Claude_*\LocalCache\Roaming\Claude\Claude Extensions\local.mcpb.mcp-interfaces.mailbridge-spm", "$env:APPDATA\Claude\Claude Extensions\local.mcpb.mcp-interfaces.mailbridge-spm" -ErrorAction SilentlyContinue)[0].FullName; $b
node "$b\dist\src\mcp\start.cjs" --setup
If the first line prints nothing, step 3 is not done yet. If PowerShell does not know “node”, use the full path, for example: & "C:\Program Files\nodejs\node.exe" "$b\dist\src\mcp\start.cjs" --setup
Setup asks whether the AI may send directly (recommended: no) and which accounts the AI may see (Thunderbird shows the ids such as “account1” under Add-ons and Themes › MailBridge for Thunderbird › “Options”, on macOS “Preferences”, section “Accounts”), and suggests a folder for attachments. Nothing is written until I answer “yes”.

Step 6 – Quit Thunderbird and Claude Desktop once and start them again.

If something goes wrong: message “not_configured” → repeat step 5. No connection to Thunderbird → Thunderbird must be running and the add-on enabled, then restart Thunderbird. Message “untrusted_peer” → restart Thunderbird and the AI app. Everything else: guide at https://mcp-interfaces.com/mailbridge/guide.html#thunderbird

Thunderbird: defaults

• The AI sees no account and no address book until you share it.
• The AI never sends on its own. It opens a compose window, and you send. Direct sending works only if you turn it on in two places (setup and Thunderbird).
• Nothing is deleted permanently unless you allow it yourself. "Delete" means: move to Trash. Emptying Trash and Junk and deleting contacts work only if you turn them on, and the AI has to confirm each time.
• Attachments only from folders you allow.

Thunderbird: requirements

• Thunderbird 128 or newer (tested with 153 on macOS and 156 on Windows), macOS or Windows 11
• Node.js 20 or newer – for setup (step 3) and for the MailBridge helper program that Thunderbird starts. You need it even though Claude Desktop brings its own Node.js: Claude Desktop uses its built-in Node.js only for itself (its settings may say "Node.js: not found (built-in: …)" – that is fine). Download: https://nodejs.org ("LTS" version).
• An AI app with MCP, for example Claude Desktop

Thunderbird: installation

Download the files MailBridge-for-Thunderbird-<version>.mcpb and MailBridge-for-Thunderbird-<version>.xpi from the product page.

1. Install in Claude Desktop. Settings › Extensions › Advanced settings › "Install Extension…", choose the .mcpb file and confirm the installation. The extension "MailBridge for Thunderbird" is enabled right away.

2. Install in Thunderbird. Add-ons and Themes › gear icon › "Install Add-on From File…" › choose the .xpi file and confirm with "Add". The add-on only asks for the basic permissions (read accounts and messages, compose, move, talk to the helper program). Sending and address books are not among them – you allow those yourself later if you want.

3. Run setup. Once, in Terminal (Mac) or PowerShell (Windows). The command asks everything, shows it, and writes only after your "yes":

Mac:

node "$HOME/Library/Application Support/Claude/Claude Extensions/local.mcpb.mcp-interfaces.mailbridge-spm/dist/src/mcp/start.cjs" --setup

Windows (PowerShell) – two lines. The first one finds the extension folder: current Claude Desktop versions for Windows are an app package and keep it under %LOCALAPPDATA%\Packages\Claude_…\LocalCache\Roaming\Claude\, other installations under %APPDATA%\Claude\.

$b = @(Get-Item "$env:LOCALAPPDATA\Packages\Claude_*\LocalCache\Roaming\Claude\Claude Extensions\local.mcpb.mcp-interfaces.mailbridge-spm", "$env:APPDATA\Claude\Claude Extensions\local.mcpb.mcp-interfaces.mailbridge-spm" -ErrorAction SilentlyContinue)[0].FullName; $b
node "$b\dist\src\mcp\start.cjs" --setup

The first line prints the folder it found. If it prints nothing, the extension is not installed yet (step 1).

If PowerShell does not know node (Node.js is not in the PATH), use the full path to node.exe instead, for example & "C:\Program Files\nodejs\node.exe" "$b\dist\src\mcp\start.cjs" --setup.

Setup

• first asks whether the AI may send directly (default: no),
• asks which accounts the AI may see. Thunderbird shows the ids (e.g. account1) under Add-ons and Themes › MailBridge for Thunderbird › "Options" (on macOS "Preferences"), section "Accounts". Leaving it empty means: no account,
• suggests a folder of its own for attachments in your home folder: mailbridge-attachments (English system) or mailbridge-anhaenge (German system),
• registers the helper program for Thunderbird and writes the settings file. An existing settings file is backed up first.

It changes nothing in your Thunderbird profile and nothing in Claude Desktop. --dry-run only shows what would be written.

4. Restart. Quit Thunderbird and Claude Desktop once and start them again.

Thunderbird: updating

Download the new files and install them the same way as the first time – no new setup is needed, your settings and permissions stay as they are.

• Claude Desktop: install the new .mcpb (Settings › Extensions › Advanced settings › "Install Extension…"). The preview offers an update; confirm it, and confirm the installation that follows. The extensions page does not show a version number.
• Thunderbird: "Install Add-on From File…" with the new .xpi. The question offers "Add" – this replaces the installed version; there is still only one MailBridge entry. The "Options" tab (on macOS "Preferences") may only appear after you open the add-on again.
• Then restart Thunderbird and Claude Desktop.

Both files must have the same version number; if they don't, every tool answers with a message naming both versions.

Thunderbird: changing what is shared

The settings file is here:

• Mac: ~/Library/Application Support/mailbridge-spm/config.json
• Windows: %LOCALAPPDATA%\mailbridge-spm\config.json

Entry	Meaning	Default
allowed_accounts	Accounts the AI sees, e.g. ["account1"]	none
allow_direct_send	The AI may send directly (in addition to the permission in Thunderbird)	false
attachment_dirs	Folders the AI may attach files from	none
allow_move	Move and copy messages	false
allow_delete	Move messages and folders to Trash	false
allowed_address_books	Address books the AI sees (ids from the options page)	none
allow_contact_write	Create, change and (with confirmation) delete contacts	false
save_dirs	Folders the AI may save attachments to (otherwise only its own cache folder)	none
allow_permanent_delete	Empty Trash and Junk permanently (in addition to the permission in Thunderbird)	false
allow_tag_write	Create, change and delete tags (in addition to the permission in Thunderbird)	false

After a change, restart Thunderbird and your AI app. Taking something away or turning something off works immediately.

In Thunderbird (Add-ons and Themes › MailBridge for Thunderbird › "Options", on macOS "Preferences") you allow – if you want – sending, access to address books, permanent deletion (emptying Trash and Junk) and changing tags. The page also shows which accounts and address books are shared.

Mail and contact details from shared accounts and address books are passed to your AI app as soon as the AI asks for them. Share only what the AI may see.

Thunderbird: troubleshooting

• "not_configured": the settings file is missing or invalid – run setup.
• No connection to Thunderbird: Thunderbird must be running and the add-on enabled. After setup, restart Thunderbird once.
• "untrusted_peer": restart Thunderbird and the AI app. If the message stays, another program may be running under the name of MailBridge.

IMAP: let your AI guide you

Copy this text into your AI app (for example a new chat in Claude Desktop). The AI guides you step by step through the installation – it does not install anything itself.

Copy text

Please guide me step by step through installing “MailBridge for IMAP” (an interface between my email account and my AI app, without a mail program). Stick strictly to the details below; do not invent any further steps, commands or settings. Do not run anything on my computer yourself. Give me one step at a time, wait for my reply and ask before continuing. First ask me whether I use a Mac or Windows 11 and which provider my account is with (GMX, WEB.DE, T-Online, STRATO, Gmail, iCloud Mail, Yahoo Mail or another one), and then show me only the matching details.

Requirements: macOS or Windows 11; Claude Desktop (or another AI app with MCP); Node.js version 20 or later; an email account with IMAP access.

Step 1 – At the provider: GMX and WEB.DE: switch on IMAP in the mailbox settings in the web mail (the provider's help page shows where). T-Online: have a separate “password for e-mail programs” (“Passwort für E-Mail-Programme”) ready – not the password of the Telekom login. STRATO: the user name is the full email address. Gmail, iCloud Mail and Yahoo Mail: choose “other provider” in the setup and use an app password. Gmail – IMAP imap.gmail.com, port 993, TLS; SMTP smtp.gmail.com, port 465, TLS; app password at https://myaccount.google.com/apppasswords (2-Step Verification must be on). iCloud Mail – IMAP imap.mail.me.com, port 993, TLS; SMTP smtp.mail.me.com, port 587, STARTTLS; the user name is the full iCloud address; app-specific password at https://account.apple.com under “App-Specific Passwords” (two-factor authentication must be on). Yahoo Mail – IMAP imap.mail.yahoo.com, port 993, TLS; SMTP smtp.mail.yahoo.com, port 465, TLS; the user name is the full address; app password in the Yahoo Account Security page via “Create app password”. Other providers: have server, port and encryption (TLS or STARTTLS) for IMAP and for outgoing mail (SMTP) from the provider's help page ready; if the provider requires an app password, use that.

Step 2 – Node.js: download and install the “LTS” version from https://nodejs.org.

Step 3 – File: download the .mcpb file under “MailBridge for IMAP” from https://mcp-interfaces.com/mailbridge/.

Step 4 – Claude Desktop: Settings › Extensions › Advanced settings › “Install Extension…”, choose the .mcpb file and confirm the installation.

Step 5 – Setup, once per account. Mac: open the “Terminal” app and paste this command:
node "$HOME/Library/Application Support/Claude/Claude Extensions/local.mcpb.mcp-interfaces.mailbridge-imap/dist/src/imap/start.cjs" --setup
Windows: open “PowerShell” and paste these two lines one after the other:
$b = @(Get-Item "$env:LOCALAPPDATA\Packages\Claude_*\LocalCache\Roaming\Claude\Claude Extensions\local.mcpb.mcp-interfaces.mailbridge-imap", "$env:APPDATA\Claude\Claude Extensions\local.mcpb.mcp-interfaces.mailbridge-imap" -ErrorAction SilentlyContinue)[0].FullName; $b
node "$b\dist\src\imap\start.cjs" --setup
If the first line shows nothing, or Terminal reports “Cannot find module”, step 4 is not done yet. If PowerShell does not know “node”, use the full path, for example: & "C:\Program Files\nodejs\node.exe" "$b\dist\src\imap\start.cjs" --setup
The setup speaks English or German, following the language of the computer (add --lang en or --lang de to choose), and asks in this order: whether the AI may send directly (recommended: no, “n”), provider, email address, user name (Enter takes the address), sender name, short name of the account, servers (Enter takes the preset), password (typing stays invisible; the login is checked and the password stored in the macOS Keychain or the Windows Credential Manager), and finally whether the AI may see the account – answer “y” for yes.

Step 6 – Quit Claude Desktop once and start it again.

Troubleshooting: “rejected the user name or password” → check user name and password (with T-Online the “password for e-mail programs”), then repeat step 5, enter the same short name and confirm “replace” with “y”. “refused IMAP access” → with GMX or WEB.DE switch on IMAP in the web mail. “No password is stored” → repeat step 5 for the account. Gmail: the AI only finds archived emails if, in the Gmail settings under Labels, the box “In IMAP anzeigen” (show in IMAP) is ticked for “Alle E-Mails” (all mail) – labels as seen in the German Gmail interface. The AI sees no account → answer the sharing question in step 5 with “y”, then restart Claude Desktop. Everything else: guide at https://mcp-interfaces.com/mailbridge/guide.html#imap

IMAP: set this up at your provider first

• GMX and WEB.DE: IMAP must be switched on in the settings of your mailbox (in the web mail). The help pages say (in German): „Um POP3 oder IMAP nutzen zu können, müssen Sie diese Funktion in den GMX Einstellungen einschalten“ – to use POP3 or IMAP, switch this function on in the GMX settings (WEB.DE accordingly). Your provider's help page shows where.
• T-Online (Telekom): You need a separate “password for e-mail programs” („Passwort für E-Mail-Programme“) – not the password of your Telekom login.
• STRATO: The user name is the full email address.
• Gmail: Choose “other provider” in the setup. IMAP imap.gmail.com, port 993, TLS; SMTP smtp.gmail.com, port 465, TLS; the user name is the full address. Use an app password instead of your Google password (create it at myaccount.google.com/apppasswords; 2-Step Verification must be on). In Gmail, archived emails are only in “All Mail” (shown to mail programs as „Alle Nachrichten“ in the German interface): for the AI to find them, the box “In IMAP anzeigen” (show in IMAP) must be ticked for “Alle E-Mails” (all mail) in the Gmail settings under Labels.
• iCloud Mail: “other provider”. IMAP imap.mail.me.com, port 993, TLS; SMTP smtp.mail.me.com, port 587, STARTTLS; the user name is the full iCloud address. Use an app-specific password instead of your Apple password (at account.apple.com under “App-Specific Passwords”; two-factor authentication must be on). Note: emails iCloud classifies as junk are in the “Junk” folder – the AI only searches there if you explicitly ask it to.
• Yahoo Mail: “other provider”. IMAP imap.mail.yahoo.com, port 993, TLS; SMTP smtp.mail.yahoo.com, port 465, TLS; the user name is the full address. Use an app password instead of your Yahoo password (in the Yahoo Account Security page via “Create app password”). These details come from Yahoo's help page.
• Other providers: Have server, port and encryption (TLS or STARTTLS) for IMAP and for outgoing mail (SMTP) at hand – they are on your provider's help page. If your provider requires an app password for mail programs, use that.

IMAP: installation and setup

Download the file MailBridge-for-IMAP-<version>.mcpb from the product page.

1. Install in Claude Desktop. Settings › Extensions › Advanced settings › “Install Extension…”, choose the .mcpb file and confirm the installation.

2. Run setup – once per account in Terminal (Mac) or PowerShell (Windows). The settings file is written only at the end.

Mac:

node "$HOME/Library/Application Support/Claude/Claude Extensions/local.mcpb.mcp-interfaces.mailbridge-imap/dist/src/imap/start.cjs" --setup

If Terminal reports “Cannot find module”, the extension is not installed yet (step 1).

Windows (PowerShell) – two lines; the first one finds the extension folder:

$b = @(Get-Item "$env:LOCALAPPDATA\Packages\Claude_*\LocalCache\Roaming\Claude\Claude Extensions\local.mcpb.mcp-interfaces.mailbridge-imap", "$env:APPDATA\Claude\Claude Extensions\local.mcpb.mcp-interfaces.mailbridge-imap" -ErrorAction SilentlyContinue)[0].FullName; $b
node "$b\dist\src\imap\start.cjs" --setup

If the first line shows nothing, the extension is not installed yet. If PowerShell does not know node, use the full path, for example & "C:\Program Files\nodejs\node.exe" "$b\dist\src\imap\start.cjs" --setup.

The setup speaks English or German, following the language of your computer; add --lang en or --lang de to choose. With --dry-run after --setup, it only shows what it would write (it does not ask for the password). The questions in order:

1. Sending: May the AI send directly? Default: no – then it only saves drafts.
2. Provider: GMX, WEB.DE, T-Online, STRATO or “other provider” – also for Gmail, iCloud Mail and Yahoo Mail (server details above).
3. Email address and user name (usually the full address; Enter takes it).
4. Sender name: the name recipients see. Leave it empty: the draft then shows only the address.
5. Short name of the account, e.g. gmx – the AI knows the account by this name. If it exists already, the setup asks whether to replace the existing account (default: no).
6. Servers for IMAP and SMTP: preset for the four providers (Enter takes them); otherwise enter server, encryption and port.
7. Password or app password: Your typing stays invisible. MailBridge checks the login and only then stores the password in the macOS Keychain or the Windows Credential Manager. On Windows it stays on this computer.
8. Sharing: May the AI see this account? Default: no.

3. Restart Claude Desktop.

IMAP: sharing, updating, limits

The settings file is here:

• Mac: ~/Library/Application Support/mailbridge-imap/config.json
• Windows: %LOCALAPPDATA%\mailbridge-imap\config.json

Entry	Meaning	Default
allowed_accounts	Short names of the accounts the AI sees, e.g. ["gmx"]	none
allow_direct_send	The AI may send saved drafts	false
allow_move	Move messages and folders, copy messages	false
allow_delete	Move messages and folders to the trash	false
attachment_dirs	Folders the AI may attach files from	none
save_dirs	Folders the AI may save attachments to (otherwise only its own cache folder)	none
language	Language of quote and forward headers: "de" or "en"	"de"

Stop sharing: remove the short name from allowed_accounts – this takes effect immediately. Share or switch something on: add the entry or set it to true, then restart Claude Desktop. Passwords never belong in this file.

Updating: install the new .mcpb file like the first time; settings and passwords are kept. Then restart Claude Desktop.

Limits: Searching the text can be slow in large mailboxes; if the server does not answer in time, MailBridge reads the latest messages itself and says explicitly when the result may be incomplete – then narrow the search by folder and date range. Login only with user name and password or app password. No filters, address books or calendars; nothing is deleted permanently.

IMAP: troubleshooting

The tools' messages are in English; they name account and server, never the password.

• “No configuration file found” or “… is invalid”: run the setup or fix the entry named.
• “rejected the user name or password”: check user name (usually the full address) and password – with T-Online the “password for e-mail programs”. Then run the setup again, enter the same short name and confirm “replace” with y.
• “refused IMAP access”: with GMX and WEB.DE switch on IMAP in the mailbox settings.
• “No password is stored”: run the setup for the account again.
• “A secure connection … could not be established” or “Cannot connect”: check server, port and encryption. Usual are port 993 with TLS or 143 with STARTTLS for IMAP, and 465 with TLS or 587 with STARTTLS for outgoing mail. MailBridge never connects unencrypted.
• “did not answer in time”: try again later; narrow a search.
• “… is switched off (allow_move …)” or “(allow_delete …)”: moving or deleting is switched off; nothing was changed.

Apple Mail: let your AI guide you

Copy this text into your AI app (for example a new chat in Claude Desktop). The AI guides you step by step through the installation – it does not install anything itself.

Copy text

Please guide me step by step through installing “MailBridge for Apple Mail” (an interface between the Mail app on my Mac and my AI app). Stick strictly to the details below; do not invent any further steps, commands or settings. Do not run anything on my computer yourself. Give me one step at a time, wait for my reply and ask before moving on.

Requirements: a Mac with Apple Mail and at least one account set up in it; Claude Desktop (or another AI app with MCP); Node.js version 20 or later. MailBridge for Apple Mail never sends; it saves new messages, replies and forwards only as drafts. Drafts with your own text need the password of the mail server per account (an app-specific password for iCloud and Google).

Step 1 – Node.js: download and install the “LTS” version from https://nodejs.org.

Step 2 – File: from https://mcp-interfaces.com/mailbridge/ under “MailBridge for Apple Mail”, download the .mcpb file.

Step 3 – Claude Desktop: Settings › Extensions › Advanced settings › “Install Extension”, choose the .mcpb file and confirm with “Install”.

Step 4 – Setup: open the “Terminal” app and paste this command:
node "$HOME/Library/Application Support/Claude/Claude Extensions/local.mcpb.mcp-interfaces.mailbridge-applemail/dist/src/applemail/start.cjs" --setup
If Terminal reports “Cannot find module”, step 3 is not done yet. The setup announces that macOS will ask whether “Terminal” may control the app “Mail” – click “Allow” or “OK”. It then lists the accounts from Mail and asks for each account whether the AI may see it (for the account you want, “y” and a short name, e.g. “private”), for each shared account the password of the mail server for drafts with your own text (your input stays invisible, Enter skips), whether the AI may move and copy messages and whether it may put messages in the trash (recommendation for both: no for now), and for two folders for attachments (Enter takes the suggestion, “-” means none). It saves only after you confirm. The setup speaks English or German, following the language of the Mac; add --lang en or --lang de to choose.

Step 5 – Quit Claude Desktop once and start it again. On the first access, macOS asks again, this time for “Claude” – allow it as well.

If something goes wrong: “No configuration file found” → run step 4. “macOS does not allow controlling Apple Mail” → System Settings › Privacy & Security › Automation › for the app (Terminal or Claude) switch on “Mail”. “Apple Mail is not running and could not be reached” → open Mail once. The AI sees no account → repeat step 4 and answer “y” for sharing, then restart Claude Desktop. Everything else: guide at https://mcp-interfaces.com/mailbridge/guide.html#applemail

Apple Mail: installation and setup

Download the file MailBridge-for-Apple-Mail-<version>.mcpb from the product page.

1. Install in Claude Desktop. Settings › Extensions › Advanced settings › “Install Extension”, choose the .mcpb file and confirm with “Install”.

2. Run setup – once in Terminal. The command reads the list of your accounts from Mail, asks everything and writes the settings file only at the end:

node "$HOME/Library/Application Support/Claude/Claude Extensions/local.mcpb.mcp-interfaces.mailbridge-applemail/dist/src/applemail/start.cjs" --setup

If Terminal reports “Cannot find module”, the extension is not installed yet (step 1). With --dry-run after --setup, the setup only shows what it would write. It speaks English or German, following the language of your Mac; add --lang en or --lang de to choose.

The setup asks in turn:

1. Notice: macOS is about to ask whether “Terminal” may control the app “Mail” – click “Allow” or “OK”. If Mail is not running, it is started.
2. Sharing per account: may the AI see this account? Default: no. If yes, a short name (lower case, no spaces, e.g. private) – the AI knows the account by this name.
3. Drafts with your own text: for every shared account the password of the mail server. Your input stays invisible; Enter skips the account. The setup checks the login and puts the password into the macOS Keychain only when saving. iCloud and Google need an app-specific password from the provider.
4. Moving and copying (allow_move) – default: no.
5. Trash (allow_delete) – default: no. Nothing is ever deleted permanently.
6. Folder for saved attachments – suggestion ~/mailbridge-attachments; Enter takes it, “-” means none.
7. Folder the AI may attach files from – for drafts with your own text and when forwarding as an attachment; Enter takes it, “-” means none.
8. Saving: only after you confirm; only you can read the file.

3. Restart Claude Desktop. On the first access, macOS asks again, this time for “Claude” – allow it as well.

Apple Mail: sharing, updating, limits

The settings file is here: ~/Library/Application Support/mailbridge-applemail/config.json

Entry	Meaning	Default
allowed_accounts	Short names of the accounts the AI sees, e.g. ["private"]	none
allow_move	Move and copy messages	false
allow_delete	Put messages in the trash	false
save_dirs	Folders the AI may save attachments into (otherwise only its own cache folder)	none
attachment_dirs	Folders the AI may attach files from	none
accounts[].server	Mail server, port and user for drafts with your own text (written by the setup; the password is in the Keychain)	none
start_mail_visible	If Mail is not running, MailBridge starts it visibly (true) or in the background (false)	true

Withdraw sharing: remove the short name from allowed_accounts – this takes effect at once – or run the setup again and answer “no”; this also removes the account's password from the Keychain. Passwords never belong in the settings file. Share or switch something on: add the entry or set it to true, then restart Claude Desktop. You withdraw the permission to control Mail in System Settings › Privacy & Security › Automation.

Updating: install the new .mcpb file as the first time; the settings are kept. Then restart Claude Desktop. If you come from version 0.2.0 and want drafts with your own text, run the setup once more and enter the password.

Limits: macOS only, only with Apple Mail. No sending; everything is saved as a draft. Your own text only for accounts with a password from the setup; otherwise no new messages and replies, and forwards without your own text. No tags, no permanent deletion, folders cannot be moved or deleted. The search reads Mail folder by folder – with very many folders, Inbox, Sent, Drafts and Archive are searched first.

Other AI apps: command node, argument the path to dist/src/applemail/start.cjs in the installed package (see step 2). On the first access, macOS asks whether this app may control Mail.

Removing: run the same command as in step 2 with --uninstall instead of --setup (it asks first; it also removes the passwords for drafts from the Keychain; saved attachments stay), then remove the extension in Claude Desktop and switch off the control of Mail in System Settings › Privacy & Security › Automation.

Apple Mail: if something does not work

• “No configuration file found” or “… is invalid”: run the setup or fix the entry named.
• “macOS does not allow controlling Apple Mail”: System Settings › Privacy & Security › Automation › for the app (Terminal or Claude) switch on “Mail”.
• “Apple Mail is not running and could not be reached”: open Mail once and try again.
• “did not finish in time” or an incomplete search: narrow the search with a folder and a period.
• “… is switched off (allow_move …)” or “(allow_delete …)”: moving or the trash is switched off; nothing was changed.
• “… needs an account that is set up for drafts with your own text” or “No password is stored for account …”: the password of the mail server is missing for this account – run the setup again and enter it.
• “Login failed” or similar for a draft: the password has changed – run the setup again and enter the new one.
• A draft is missing in Mail (messageId: null): the draft is saved on the mail server. Apple Mail shows it in the Drafts folder after its next synchronization – this can take a few minutes. Mailbox › Synchronize makes it faster.
• A message is not found after moving it: moving, copying, putting into the trash and renaming its folder give a message a new id; the AI finds it again with a search.

Both editions: other AI apps

MailBridge is an ordinary local MCP server (stdio). Enter this command in your app:

• command: node
• argument: the path to dist/src/mcp/start.cjs (Thunderbird) or dist/src/imap/start.cjs (IMAP) in the installed package (see installation) – or, without Claude Desktop, in a folder where you unpacked the .mcpb file (it is a ZIP archive).

Example GitHub Copilot CLI, file ~/.copilot/mcp-config.json:

{
  "mcpServers": {
    "mailbridge-spm": {
      "type": "local",
      "command": "node",
      "args": ["<path>/dist/src/mcp/start.cjs"],
      "env": {},
      "tools": ["*"]
    }
  }
}

What is shared is the same for every app – it is set in the settings file (and, for Thunderbird, in Thunderbird), not in the AI app.

Both editions: removing

Thunderbird:

1. Remove the helper program registration – before removing the extension in Claude Desktop – with the same command as in the setup, but --uninstall instead of --setup. It asks first.
2. Remove the extension in Claude Desktop and the add-on in Thunderbird.
3. The settings file and the log are in the folder named above and can be deleted.

IMAP:

1. Remove passwords and settings – first, with the same command as in the setup, but --uninstall instead of --setup. After one confirmation it removes the passwords of all accounts in the settings file and then the settings file; saved attachments stay. With --dry-run added it only shows what it would remove.
2. Remove the extension in Claude Desktop.
3. Only one account: --remove-password <short name> instead of --setup removes its password and leaves the settings file unchanged. On the Mac this also works in Keychain Access (entries “mailbridge-imap:<short name>”).

Trademarks

Thunderbird is a trademark of the Mozilla Foundation. MailBridge is not affiliated with or endorsed by the Mozilla Foundation. GMX, WEB.DE, T-Online and STRATO are named only to describe the preset server settings, Gmail, iCloud Mail and Yahoo Mail only to describe the setup; MailBridge is not affiliated with these providers. Apple, Apple Mail, Mail and macOS are named only to describe the program MailBridge for Apple Mail works with; they are trademarks of Apple Inc. MailBridge is not affiliated with Apple.

Licence

Free to use; passing it on is not allowed – see the licence and terms of use.