Dead Letter MCP Server

Your .eml files deserve a second life. dead-letter converts email exports into clean Markdown with YAML front matter - threads split, signatures stripped, attachments extracted, calendars parsed. One file or ten thousand. It runs locally over stdio via the published package.

People connecting email tools to Claude, Cursor, VS Code, or another MCP client. The project is written in Python.

VERIFIED ACTIVE

LAST COMMIT 2026-08-21 · ★ 6 · #28 OF 75 MAINTAINED EMAIL · VERIFIED 2026-08-25

NOASSERTION · Python servers · how we verify → /methodology

01 · Install Dead Letter

Claude Code

claude mcp add bigcactuslabs-dead-letter -- uvx dead-letter

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "bigcactuslabs-dead-letter": {
      "command": "uvx",
      "args": [
        "dead-letter"
      ]
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions

license no standard license detected - usage rights unclear; check the repo before commercial use

pypi package dead-letter - check the name against the project README before installing (PyPI has no namespace ownership)

registry namespace io.github.BigCactusLabs is GitHub-verified and matches the repo owner

03 · What Dead Letter can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

Latest releases

v0.2.5 · 2026-08-21

MCP works again in clean installs · dead-letter[mcp] now uses MCP Python SDK 2.x (mcp>=2,<3) and its public MCPServer API. This fixes the startup failure from the removed mcp.server.fastmcp module in newly resolved…

v0.2.4 · 2026-07-06

Added · Official MCP Registry publishing. A server.json describes the · dead-letter-mcp server, and a publish-mcp job in the release workflow · publishes it to registry.modelcontextprotocol.io after each PyPI release…

v0.2.3 · 2026-06-09

Added · Added diagnostics.attachments {referenced, retained} counts for attachment-retention visibility. · Added Claude plugin content tests for the untrusted-email-content contract. · Changed · Bumped Claude plugin…

04 · Who maintains Dead Letter

dead-letter is maintained by bigcactuslabs. It's the only MCP server we track from this author; the repo dates to Mar 2026.

05 · Facts

repository: github.com/bigcactuslabs/dead-letter
category: email - ranked #28 of 75 actively-maintained email servers as of 2026-08-25.
release cadence: 5 releases in the last 90 days (latest 2026-08-21)
registry: io.github.BigCactusLabs/dead-letter (active, first published 2026-07-06 · 2 versions)
packages: pypi:dead-letter

06 · Dead Letter FAQ

What is Dead Letter?

Is Dead Letter still maintained?

Yes - as of 2026-08-25, its last commit was 2026-08-21 and it shipped 5 releases in the last 90 days. We re-verify nightly.

How do I install Dead Letter?

Run `uvx dead-letter`. You can also paste the ready-made client config above.

Does Dead Letter run locally?

Yes - it's a stdio server: it runs on your machine (via uvx) with your user's permissions. Your data stays local unless the server itself calls external APIs.

07 · Alternatives to Dead Letter

Alternatives to Dead Letter

Maintained email servers if Dead Letter isn't the fit.

More email MCP servers · Email (IMAP/SMTP) (boutquin) · Company Enrichment API · Fluxmail · Email MCP

More Python MCP servers · Codemunch Pro · Grafyx · Openbrowser AI · Memory Arbiter MCP · Superset · see all