Proton Mail (unofficial) MCP Server

Connect this server

This server runs on your own machine — install it with the package manager and the client starts it for you. Package name taken from the official registry entry.

claude mcp add proton-mail-mcp -- npx -y proton-mail-mcp

{
  "mcpServers": {
    "proton-mail-mcp": {
      "args": [
        "-y",
        "proton-mail-mcp"
      ],
      "command": "npx"
    }
  }
}

[mcp_servers.proton-mail-mcp]
command = "npx"
args = ["-y", "proton-mail-mcp"]

{
  "mcpServers": {
    "proton-mail-mcp": {
      "args": [
        "-y",
        "proton-mail-mcp"
      ],
      "command": "npx"
    }
  }
}

{
  "mcpServers": {
    "proton-mail-mcp": {
      "args": [
        "-y",
        "proton-mail-mcp"
      ],
      "command": "npx"
    }
  }
}

This one needs environment variables set before it will start: PROTONMAIL_USERNAME (Your Proton Mail email address), PROTONMAIL_PASSWORD (Your Proton Mail SMTP password (not your login password; generate one in Proton settings)), PROTONMAIL_HOST (SMTP host), PROTONMAIL_PORT (SMTP port), PROTONMAIL_SECURE (Use TLS for SMTP (true for port 465)), IMAP_HOST (Proton Mail Bridge IMAP host (required for read/search tools)), IMAP_PORT (Proton Mail Bridge IMAP port), IMAP_SECURE (Use TLS for IMAP), IMAP_USERNAME (Proton Mail Bridge username (falls back to PROTONMAIL_USERNAME)), IMAP_PASSWORD (Proton Mail Bridge password (falls back to PROTONMAIL_PASSWORD)), READONLY (Disable all mutating tools (send, move, delete, flags, labels, bulk ops, folder/label management)), RESTRICT_OUTBOUND_TO_SELF (Refuse live sends to any recipient other than PROTONMAIL_USERNAME (for throwaway/QA accounts)), ALLOW_FILE_DOWNLOAD_DIR (Allowlist directory enabling download_attachment.saveTo; when unset, attachments return as inline base64), ALLOW_EMPTY_FOLDER (Register the empty_folder tool (not recommended)), DEBUG (Enable verbose logging to stderr). The author declared them in the registry entry; get the values from the project itself.