# dead-letter (oci · ghcr.io/bigcactuslabs/dead-letter)

Convert .eml and .mbox email to clean Markdown for RAG, LLM pipelines, and local knowledge bases

- Trust score: 40/100 (low)
- Change this week: −4
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- mcpb · `dead-letter-mcp-0.4.10.mcpb`: 44/100, [markdown](https://verifymcp.io/servers/bigcactuslabs-dead-letter/https-github-com-bigcactuslabs-dead-letter-releases-download-v0-4-0-dead-letter.md), [page](https://verifymcp.io/servers/bigcactuslabs-dead-letter/https-github-com-bigcactuslabs-dead-letter-releases-download-v0-4-0-dead-letter)
- oci · `ghcr.io/bigcactuslabs/dead-letter`: 40/100 (this document), [markdown](https://verifymcp.io/servers/bigcactuslabs-dead-letter/ghcr-io-bigcactuslabs-dead-letter.md), [page](https://verifymcp.io/servers/bigcactuslabs-dead-letter/ghcr-io-bigcactuslabs-dead-letter)
- pypi · `dead-letter`: 47/100, [markdown](https://verifymcp.io/servers/bigcactuslabs-dead-letter/dead-letter.md), [page](https://verifymcp.io/servers/bigcactuslabs-dead-letter/dead-letter)

## Channel facts

- Registry: `oci`
- Package: `ghcr.io/bigcactuslabs/dead-letter`
- Version: `sha256:08699fa81fd5be51b12cdbcbbcdd4333f8a2dd9d928d79ca1b9e34473beac8af`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Supply Chain Security**: 0/100
  - No malware scan is available for this kind of package: the supply-chain vendors we use do not cover it. This is a permanent gap in our coverage, not a finding about the package.
  - Known CVEs could not be checked: this image's dependency list comes from an SBOM its publisher attached, which nothing verifies, so we will not report it as a clean result.
  - Install-script risk not yet assessed.
  - Dependency health could not be checked: this image's dependency list comes from an SBOM its publisher attached. It names packages and versions but not whether each is deprecated, still maintained or linked to its source, so there is nothing we can fairly grade.
- **Provenance & Transparency**: 35/100
  - Source repository is publicly reachable at the declared URL.
  - Provenance check failed: no build-provenance attestation is published.
  - License check failed: the license (PolyForm-Noncommercial-1.0.0) isn't a recognized OSI-approved license.
  - Actively maintained (last published 6 days ago).
  - Publishes a security disclosure policy (SECURITY.md).
- **Schema Quality & AI Usability**: 42/100
  - AI-judged instruction clarity (fair).
  - Context-footprint check failed: tool/resource definitions use about 1267 tokens (~253/item across 5 items; 5 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 73/100
  - Stability observed for 22 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 71/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 0% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 5 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a current MCP spec version (2026-07-28).

**Unverified: 1 category.** A category scored 0 because we could not verify it: a data source with nothing on this package, evidence we could not reach, or a check we could not run. We only credit what we can confirm.

## Install

### How do I install the dead-letter MCP server?

dead-letter runs locally as a container image, launched with docker run --rm -i ghcr.io/bigcactuslabs/dead-letter@sha256:08699fa81fd5be51b12cdbcbbcdd4333f8a2dd9d928d79ca1b9e34473beac8af. The registry lists runner options for this package that are not in this command (they are not ones we reproduce, or they name another package). Check the registry entry before relying on it. Ready-made configuration for Claude, Cursor, VS Code, Codex and 3 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add bigcactuslabs-dead-letter -- docker run --rm -i ghcr.io/bigcactuslabs/dead-letter@sha256:08699fa81fd5be51b12cdbcbbcdd4333f8a2dd9d928d79ca1b9e34473beac8af
```

The registry lists runner options for this package that are not in this command (they are not ones we reproduce, or they name another package). Check the registry entry before relying on it.

### Cursor

```json
{
  "mcpServers": {
    "bigcactuslabs-dead-letter": {
      "command": "docker",
      "args": [
        "run",
        "--rm",
        "-i",
        "ghcr.io/bigcactuslabs/dead-letter@sha256:08699fa81fd5be51b12cdbcbbcdd4333f8a2dd9d928d79ca1b9e34473beac8af"
      ]
    }
  }
}
```

The registry lists runner options for this package that are not in this command (they are not ones we reproduce, or they name another package). Check the registry entry before relying on it.

### VS Code

```json
{
  "servers": {
    "bigcactuslabs-dead-letter": {
      "command": "docker",
      "args": [
        "run",
        "--rm",
        "-i",
        "ghcr.io/bigcactuslabs/dead-letter@sha256:08699fa81fd5be51b12cdbcbbcdd4333f8a2dd9d928d79ca1b9e34473beac8af"
      ]
    }
  }
}
```

The registry lists runner options for this package that are not in this command (they are not ones we reproduce, or they name another package). Check the registry entry before relying on it.

### Codex

```bash
codex mcp add bigcactuslabs-dead-letter -- docker run --rm -i ghcr.io/bigcactuslabs/dead-letter@sha256:08699fa81fd5be51b12cdbcbbcdd4333f8a2dd9d928d79ca1b9e34473beac8af
```

The registry lists runner options for this package that are not in this command (they are not ones we reproduce, or they name another package). Check the registry entry before relying on it.

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "bigcactuslabs-dead-letter": {
      "type": "local",
      "command": [
        "docker",
        "run",
        "--rm",
        "-i",
        "ghcr.io/bigcactuslabs/dead-letter@sha256:08699fa81fd5be51b12cdbcbbcdd4333f8a2dd9d928d79ca1b9e34473beac8af"
      ],
      "enabled": true
    }
  }
}
```

The registry lists runner options for this package that are not in this command (they are not ones we reproduce, or they name another package). Check the registry entry before relying on it.

### Hermes

```yaml
mcp_servers:
  bigcactuslabs-dead-letter:
    command: "docker"
    args: ["run", "--rm", "-i", "ghcr.io/bigcactuslabs/dead-letter@sha256:08699fa81fd5be51b12cdbcbbcdd4333f8a2dd9d928d79ca1b9e34473beac8af"]
```

The registry lists runner options for this package that are not in this command (they are not ones we reproduce, or they name another package). Check the registry entry before relying on it.

### Netclaw

```json
{
  "McpServers": {
    "bigcactuslabs-dead-letter": {
      "Transport": "stdio",
      "Command": "docker",
      "Arguments": [
        "run",
        "--rm",
        "-i",
        "ghcr.io/bigcactuslabs/dead-letter@sha256:08699fa81fd5be51b12cdbcbbcdd4333f8a2dd9d928d79ca1b9e34473beac8af"
      ]
    }
  }
}
```

The registry lists runner options for this package that are not in this command (they are not ones we reproduce, or they name another package). Check the registry entry before relying on it.

### Other

```json
{
  "mcpServers": {
    "bigcactuslabs-dead-letter": {
      "command": "docker",
      "args": [
        "run",
        "--rm",
        "-i",
        "ghcr.io/bigcactuslabs/dead-letter@sha256:08699fa81fd5be51b12cdbcbbcdd4333f8a2dd9d928d79ca1b9e34473beac8af"
      ]
    }
  }
}
```

The registry lists runner options for this package that are not in this command (they are not ones we reproduce, or they name another package). Check the registry entry before relying on it.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-03 (score 40, −4)

- [functional] Stability: pass → 0.67

### 2026-10-29 (score 44, 0)

- [functional] Package version: sha256:0023516c85b2e5464d7a73cf037289f43d4aa8f44f13dbb6f4e09f5b9f9fa8c7 → sha256:08699fa81fd5be51b12cdbcbbcdd4333f8a2dd9d928d79ca1b9e34473beac8af

### 2026-10-28 (score 44, 0)

- [security] Stability: 0.97 → pass

### 2026-10-27 (score 44, +1)

No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-25 (score 43, +1)

No change was recorded against any check on this day. Stability & Change Management went from 87 to 90. That category is still filling its 30-day observation window: 26 days of observed history at the previous scan, 27 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-23 (score 42, +1)

No change was recorded against any check on this day. Stability & Change Management went from 80 to 83. That category is still filling its 30-day observation window: 24 days of observed history at the previous scan, 25 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-22 (score 41, 0)

- [functional] Package version: sha256:ed4b3665a6d76362d9a1835fe6511c7906524acde3484331fa62998af6e1f30c → sha256:0023516c85b2e5464d7a73cf037289f43d4aa8f44f13dbb6f4e09f5b9f9fa8c7

### 2026-10-21 (score 41, +1)

No change was recorded against any check on this day. Stability & Change Management went from 73 to 77. That category is still filling its 30-day observation window: 22 days of observed history at the previous scan, 23 at this one. The score rises as the window fills, whether or not the server changes.

## MCP tools (5)

### `convert_eml` (~295 tokens)

Convert email

Convert a .eml email file to Markdown with YAML front matter.

    Returns the full Markdown content (front matter + body). When output_path
    is provided, also writes the file to disk.

    Attachments are listed in the front matter but not written to disk; use
    convert_eml_to_bundle to save the decoded attachment files.

    thread_mode="structured" adds a section per earlier reply or forwarded
    message. Gmail HTML forwards and unquoted plain-text forwards are kept in
    latest mode too; a plain-text forward inside ">" quoting is not.

    Presets bundle common flag combinations:
    - default: strips signatures, tracking pixels, signature images
    - clean: default + strips disclaimers and quoted headers
    - verbose: includes all headers and raw HTML
    - raw: no stripping, preserves everything

    Individual flags override the preset when provided.

Input parameters:

- `embed_inline_images`
- `eml_path` (string, required)
- `include_all_headers`
- `include_raw_html`
- `no_calendar_summary`
- `output_path`
- `preset` (string)
- `strip_disclaimers`
- `strip_quoted_headers`
- `strip_signature_images`
- `strip_signatures`
- `strip_tracking_pixels`
- `thread_mode` (string)
- `thread_order` (string)

Output parameters:

- `result` (string)

### `convert_eml_to_bundle` (~236 tokens)

Convert email to bundle

Convert a .eml file to a self-contained bundle with markdown and attachments.

    Creates a directory containing the converted markdown, extracted attachments,
    and optionally the original .eml source.

    source_handling only accepts 'copy' over MCP: the original .eml is copied
    into the bundle and left untouched. The 'move' and 'delete' modes are
    rejected here — use the CLI or the Python API for those.

    Returns JSON with bundle_path, markdown_path, attachment_paths, and
    optional diagnostics.

Input parameters:

- `bundle_root` (string, required)
- `embed_inline_images`
- `eml_path` (string, required)
- `include_all_headers`
- `include_raw_html`
- `no_calendar_summary`
- `preset` (string)
- `source_handling` (string)
- `strip_disclaimers`
- `strip_quoted_headers`
- `strip_signature_images`
- `strip_signatures`
- `strip_tracking_pixels`
- `thread_mode` (string)
- `thread_order` (string)

Output parameters:

- `result` (string)

### `convert_directory` (~240 tokens)

Convert email folder

Batch convert all .eml files in a directory to Markdown.

    Recursively finds .eml files (at most 50 per call; larger directories
    are rejected before any conversion). output_directory is required:
    Markdown is written there, mirroring subfolders, and source .eml files
    are left in place. Returns a JSON summary with total, successes,
    failures, output_paths, and errors. Each errors entry contains file and
    error_code (defaulting to conversion_error), never raw exception text.

    Use convert_eml to retrieve individual converted file content.

Input parameters:

- `directory` (string, required)
- `dry_run` (boolean)
- `embed_inline_images`
- `include_all_headers`
- `include_raw_html`
- `no_calendar_summary`
- `output_directory` (string, required)
- `preset` (string)
- `strip_disclaimers`
- `strip_quoted_headers`
- `strip_signature_images`
- `strip_signatures`
- `strip_tracking_pixels`
- `thread_mode` (string)
- `thread_order` (string)

Output parameters:

- `result` (string)

### `convert_mbox` (~293 tokens)

Convert MBOX archive

Convert one flat .mbox archive (e.g. Gmail Takeout) to Markdown files.

    Bounded: the archive must be at most 256 MiB, and conversion stops after
    1000 messages (the response then has truncated=true; use the dead-letter
    CLI for larger archives). Compressed archives and Apple Mail .mbox
    directories are rejected. output_directory is required; one .md per
    message (or one bundle directory when bundles=true) is written there with a
    collision-safe JSON report. The source archive is never modified.

    Returns a JSON summary (processed, converted, skipped, failed, truncated,
    report_path, and at most 20 failure entries), never message content.
    Cancellation is not supported; byte/message caps are not a time limit.

Input parameters:

- `bundles` (boolean)
- `dry_run` (boolean)
- `embed_inline_images`
- `include_all_headers`
- `include_raw_html`
- `no_calendar_summary`
- `output_directory` (string, required)
- `path` (string, required)
- `preset` (string)
- `strip_disclaimers`
- `strip_quoted_headers`
- `strip_signature_images`
- `strip_signatures`
- `strip_tracking_pixels`
- `thread_mode` (string)
- `thread_order` (string)

Output parameters:

- `result` (string)

### `get_diagnostics` (~203 tokens)

Get conversion diagnostics

Inspect email quality and structure without writing permanent files.

    Use this to assess conversion quality before committing, or to
    troubleshoot problematic .eml files.

    Always returns JSON with: state (normal/degraded/review_recommended),
    selected_body, segmentation_path, client_hint, confidence,
    fallback_used, and warnings. Two keys are conditional: stripped_images
    appears only when images were removed, and attachments only when the
    message had attachments eligible for retention.

Input parameters:

- `embed_inline_images`
- `eml_path` (string, required)
- `include_all_headers`
- `include_raw_html`
- `no_calendar_summary`
- `preset` (string)
- `strip_disclaimers`
- `strip_quoted_headers`
- `strip_signature_images`
- `strip_signatures`
- `strip_tracking_pixels`
- `thread_mode` (string)
- `thread_order` (string)

Output parameters:

- `result` (string)

## Diagnostics

Captured diagnostic sections: Provenance, Vulnerabilities. The full working is on the page: https://verifymcp.io/servers/bigcactuslabs-dead-letter/ghcr-io-bigcactuslabs-dead-letter#diagnostics

## Score history

- 2026-11-05: 40
- 2026-11-04: 40
- 2026-11-03: 40
- 2026-11-02: 44
- 2026-11-01: 44
- 2026-10-31: 44
- 2026-10-30: 44
- 2026-10-29: 44
- 2026-10-28: 44
- 2026-10-27: 44
- 2026-10-26: 43
- 2026-10-25: 43
- 2026-10-24: 42
- 2026-10-23: 42
- 2026-10-22: 41
- 2026-10-21: 41
- 2026-10-20: 40
- 2026-10-19: 40
- 2026-10-18: 40
- 2026-10-17: 39
- 2026-10-16: 39
- 2026-10-15: 38
- 2026-10-14: 38
- 2026-10-13: 7
- 2026-10-12: 7
- 2026-10-10: 7
- 2026-10-08: 7
- 2026-10-06: 30
- 2026-10-04: 30
- 2026-10-03: 30

## Common questions

### What is the dead-letter MCP server?

dead-letter is an MCP server listed in the public MCP registry as io.github.BigCactusLabs/dead-letter. Convert .eml and .mbox email to clean Markdown for RAG, LLM pipelines, and local knowledge bases. This page covers its container image (ghcr.io/bigcactuslabs/dead-letter).

### Is the dead-letter MCP server safe to use?

dead-letter scores 40 out of 100 on VerifyMCP. The SBOM its publisher attached lists packages with 12 known advisories as of 5 November 2026. We do not grade that SBOM, as nothing verifies it. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the dead-letter MCP server expose?

dead-letter exposes 5 tools: convert_eml, convert_eml_to_bundle, convert_directory, convert_mbox, get_diagnostics. Their descriptions and schemas cost roughly 1,267 tokens of context every time the server is loaded.

### Is the dead-letter MCP server still maintained?

dead-letter is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What licence is the dead-letter MCP server under?

dead-letter declares the PolyForm-Noncommercial-1.0.0 licence, which is not on the OSI-approved list. Read the terms before using it at work, and note this covers the source only, not the cost of any service it calls.

### What did VerifyMCP test on the dead-letter MCP server?

VerifyMCP ran 12 checks on dead-letter, covering Source repository, Provenance, License, Maintenance and 8 more. 4 items could not be completed, a gap on our side rather than a finding about dead-letter: Malware scan, Known CVEs, Install scripts and Dependency health. One category scores 0 for that reason, because we only credit what we can confirm. Endpoint Security and Transport & Reachability do not apply to a container image, so they were not tested. The score does not measure everything, and the scoring documentation lists what it leaves out.

## Links

- GitHub Container Registry: https://ghcr.io/bigcactuslabs/dead-letter
- Repository: https://github.com/BigCactusLabs/dead-letter
- Changelog RSS feed: https://verifymcp.io/servers/bigcactuslabs-dead-letter/ghcr-io-bigcactuslabs-dead-letter.xml
- Changelog JSON feed: https://verifymcp.io/servers/bigcactuslabs-dead-letter/ghcr-io-bigcactuslabs-dead-letter/changelog.json
- Trust report (JSON): https://verifymcp.io/servers/bigcactuslabs-dead-letter/ghcr-io-bigcactuslabs-dead-letter.json
- HTML version of this page: https://verifymcp.io/servers/bigcactuslabs-dead-letter/ghcr-io-bigcactuslabs-dead-letter