dead-letter SKILL.md skillA
dead-letter from bigcactuslabs/dead-letter is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add bigcactuslabs/dead-letter/dead-letter@git:20261022.808ecacPins git:20261022.808ecac in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- bigcactuslabs/dead-letter
- Path
skills/dead-letter/SKILL.md- Versions recorded
- 6
- Latest version
- git:20261022.808ecac, committed Oct 22, 2026
- First version recorded
- Sep 28, 2026
- Size
- 9,292 bytes
- Repository stars
- 8
- License
- a license file GitHub does not identify
Convert .eml email files (Gmail, Outlook, Apple Mail, Thunderbird exports, email archives) to Markdown with YAML front matter for reading, summarizing, RAG, or building a local email archive. Use when a task involves a .eml file or folder, exported email, or turning email into Markdown. Runs locally via uvx or the dead-letter MCP server; treats email content as untrusted data.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# dead-letter: email (.eml) to Markdown dead-letter converts `.eml` files to Markdown with YAML front matter (subject, from, to, date, message id, attachment list) and a cleaned body. Use it instead of parsing MIME by hand whenever a task starts from exported email. ## When to use - The user points at a `.eml` file or a folder of `.eml` files. - The user wants an exported email read, summarized, searched, or turned into Markdown, notes, or a knowledge base. - The user wants a local email archive or RAG corpus built from email exports. ## Input boundary (say this instead of guessing) - The MCP server (Path 1) accepts `.eml` files, each one RFC 822 message. Version 0.4.5 and later add a bounded `convert_mbox` tool for one flat `.mbox`; 0.4.0 and earlier do not accept `.mbox`. Use it only if the server's tool list includes it. - The CLI (Path 2) also converts a flat Gmail Takeout `.mbox` file, not just `.eml`: `uvx --python 3.12 dead-letter convert "Takeout/Mail/All mail.mbox" --output markdown/`. The CLI has no archive size or message-count cap. No web UI accepts `.mbox`. An opt-in CLI `--mbox-resume` for interrupted imports is available from 0.4.6. …
Read the whole file at its exact version.
How to install
mdr add bigcactuslabs/dead-letter/dead-letter@sha256:f4c7a74a924b4ee1The line at the top of this page pins the label git:20261022.808ecac, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_qp5dvxpv5ql2csv7)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 6 versions of this file, between Sep 28, 2026 and Oct 22, 2026, about one every 5 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261022.808ecac latest | 2026-10-22 | 808ecac | 9,292 B | A | view · diff |
| git:20261006.d96907b | 2026-10-06 | d96907b | 9,297 B | A | view · diff |
| git:20261001.779325d | 2026-10-01 | 779325d | 9,315 B | A | view · diff |
| git:20260928.2263560 | 2026-09-28 | 2263560 | 9,216 B | A | view · diff |
| git:20260928.bb3d869 | 2026-09-28 | bb3d869 | 9,068 B | A | view · diff |
| git:20260928.c1a3467 | 2026-09-28 | c1a3467 | 9,011 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (9292 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
bigcactuslabs/dead-letter · 8 stars · license a license file GitHub does not identify · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_qp5dvxpv5ql2csv7 GET https://markdownregistry.com/api/v1/resolve?ref=bigcactuslabs/dead-letter/dead-letter GET https://markdownregistry.com/api/v1/blob/f4c7a74a924b4ee12d689a7ecbef16c58170b7f5fe2814b1ed37da7103c5c980
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.