MCP Notmuch Sendmail

Status: Works great and is in daily use without any known bugs.

Status2: I just added the package to PyPI and updated the usage instructions. Please report any issues :)

Let Claude be your email assistant! MCP Notmuch Sendmail connects Claude Desktop to your notmuch email database, allowing it to:

• Search and browse your email threads
• View conversations in a clean text format
• Compose new emails using markdown
• Reply to threads with smart deduplication of quoted content
• Create beautiful emails with LaTeX-inspired styling
• Synchronize your email database by running a configured script

Uses html2text for HTML email rendering and markdown-it for composing rich HTML emails with inline images.

Installation

Ensure you have uv installed:

# Install uv if you haven't already
curl -LsSf https://astral.sh/uv/install.sh | sh

Usage with Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "email": {
      "command": "uvx",
      "args": ["--from", "mcp-notmuch-sendmail==2026.09.10.084837", "--python", "3.10",
               "--refresh", "mcp-notmuch-sendmail"]
      "env": {
        "NOTMUCH_DATABASE_PATH": "/path/to/your/notmuch/db",
        "NOTMUCH_REPLY_SEPARATORS": "Pipe|Separated|Phrases",
        "SENDMAIL_FROM_EMAIL": "your.email@example.com",
        "SENDMAIL_EMAIL_SIGNATURE_HTML": "<p>Optional HTML signature</p>",
        "NOTMUCH_SYNC_SCRIPT": "/path/to/your/sync/script.sh",
        "LOG_FILE_PATH": "/path/to/log/file.log",
        "DRAFT_DIR": "/path/for/email/drafts"
      }
    }
  }
}

Transports

By default the server speaks stdio. It can also serve over HTTP for clients that connect that way:

# Recommended HTTP transport (serves on http://HOST:PORT/mcp)
mcp-notmuch-sendmail --transport streamable-http --host 127.0.0.1 --port 8000

# Legacy SSE transport, for older clients (serves on http://HOST:PORT/sse)
mcp-notmuch-sendmail --transport sse --host 127.0.0.1 --port 8000

Environment Variables

• NOTMUCH_DATABASE_PATH: Path to your notmuch database (required)
• NOTMUCH_REPLY_SEPARATORS: Pipe-separated list of text markers - keeps email content up until the first line starting with any of these markers, removing quoted replies (required)
• SENDMAIL_FROM_EMAIL: Your email address for the From: field (optional - when unset, the email composing/sending tools are disabled and the server is read-only)
• SENDMAIL_EMAIL_SIGNATURE_HTML: HTML signature to append to emails (optional)
• NOTMUCH_SYNC_SCRIPT: Path to a script for synchronizing emails (optional)
• LOG_FILE_PATH: Path for logging file (optional)
• DRAFT_DIR: Directory for storing email drafts (optional, defaults to /tmp/mcp-notmuch-sendmail)

API

Tools

• find_email_thread

  • Find email threads in the notmuch database
  • Inputs:
    • notmuch_search_query (string): The notmuch search query
    • max_threads (int, optional): Maximum number of threads to return (default: 25)
  • Returns tab-separated list of threads with format:

  thread_id    date    subject    authors
  

• view_email_thread

  • View all messages for an email thread
  • Input: thread_id (string)
  • Returns conversation in text format with HTML->text conversion (falls back to text/plain parts when a message has no HTML body)

  FROM: sender@example.com
  DATE: 2024-01-25
  Message content...
  - - -
  FROM: another@example.com
  DATE: 2024-01-24
  Earlier message...
  

• compose_new_email

  • Compose a new email draft from markdown. A signature will be automatically added if SENDMAIL_EMAIL_SIGNATURE_HTML is set.
  • Inputs:
    • subject (string): Email subject
    • body_as_markdown (string): Email body in markdown
    • to (list): Recipient email addresses
    • cc (list, optional): CC recipients
    • bcc (list, optional): BCC recipients
  • Creates draft files and returns paths:

  Created drafts:
  - /path/to/draft/dir/draft.md (edit this)
  - /path/to/draft/dir/draft.html (preview)
  

• compose_email_reply

  • Compose a reply to an existing email thread. A signature will be automatically added if SENDMAIL_EMAIL_SIGNATURE_HTML is set.
  • Inputs:
    • thread_id (string): Thread ID to reply to
    • subject (string): Email subject
    • body_as_markdown (string): Email body in markdown
    • to (list): Recipient email addresses
    • cc (list, optional): CC recipients
    • bcc (list, optional): BCC recipients
  • Creates draft files and returns paths:

  Created drafts:
  - /path/to/draft/dir/draft.md (edit this)
  - /path/to/draft/dir/draft.html (preview)
  

• send_email

  • Sends the composed email draft
  • No input required
  • Returns success/error message

• sync_emails

  • Synchronizes emails by running the configured script
  • No input required
  • Returns the script's output including stdout and stderr
  • Only available if NOTMUCH_SYNC_SCRIPT is configured

Reply Separators

The NOTMUCH_REPLY_SEPARATORS environment variable controls email reply detection. When viewing a thread, each email's content is trimmed at the first line that starts with any of the configured separators. This effectively removes quoted replies while keeping the new content.

Here are recommended separator patterns for different languages:

English

On|wrote:|From:|Sent:|To:|Subject:|Date:|Cc:|Best regards|Kind Regards|Thanks,|Thank you,|Best,|All the best|regards,|Sent from my|Get Outlook for|CAUTION:|Disclaimer:|Warning:|Confidential:|CONFIDENTIALITY:|---------- Original Message ----------

German

Am.*schrieb|Von:|Gesendet|An:|Betreff:|Datum:|Cc:|Organisation:|Mit freundlichen Grüßen|Beste Grüße|Viele Grüße|Hinweis:|Achtung:|Gesendet von

French

Le.*a écrit|De |Envoyé |À |Objet |Cc |cordialement|salutations|bonne réception|bonne journée|Envoyé depuis

Dutch

Op.*schreef:|Van:|Verzonden|Aan:|Onderwerp:|Datum:|Cc:|Met vriendelijke groet|Hartelijke groeten|Bedankt,|Dank u,|Verzonden vanaf

Italian

Il.*ha scritto:|Da:|Inviato|A:|Oggetto:|Data:|Cc:|Cordiali saluti|Inviato da

Note: Use | (pipe) to separate patterns. These are simplified patterns derived from common email clients - you may need to adjust them based on your specific needs.

Contributing

Contributions are warmly welcomed! Whether it's bug reports, feature requests, documentation improvements, or code contributions - all input is valuable. Feel free to:

• Open an issue to report bugs or suggest features
• Submit pull requests with improvements
• Enhance documentation or share your usage examples
• Ask questions and share your experiences

The goal is to make email management with Claude even better, and your insights and contributions help achieve that.

Acknowledgments

This project builds on the excellent work of others:

• mail-parser-reply - For the comprehensive email reply marker patterns
• notmuch - The fast mail indexing and search engine
• html2text - For converting HTML emails to readable text
• markdown-it-py - For generating beautiful HTML emails
• latex.css - For the LaTeX-style email formatting

License

Mozilla Public License Version 2.0

My Other LLM Projects

• MCP Alchemy - Connect Claude Desktop to databases for exploring schema and running SQL.
• MCP Redmine - Let Claude Desktop manage your Redmine projects and issues.
• Diffpilot - Multi-column git diff viewer with file grouping and tagging.
• Claude Local Files - Access local files in Claude Desktop artifacts.