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html-email

Send-ready single-file email

Skill by justinlietz93

IndexedMIT★ 23
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Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install skill/justinlietz93-html-email

Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.

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About

Send-ready single-file email

Use cases: design, frontend, productivity

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Permissions

What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.

Tools
No tools found
Secrets
None asked for
Install scripts
None found

Network hosts it talks to 1

  • codeload.github.com · found in install command

Files it touches

  • ~/.claude/skills/html-email

What's inside

Skill name
html-email
Description
Send-ready single-file email
License
MIT
Instructions
50 lines in SKILL.md · view on GitHub

Files (1)

  • SKILL.md

SKILL.md (first lines)

# HTML email

Design an HTML email as ONE self-contained .html file that survives
real email clients. Email rendering is not browser rendering — Gmail,
Outlook, and Apple Mail each strip or mangle different things, and the
rules below are what reliably survives all three. When a rule here
conflicts with normal web-design instincts, the rule wins.

Layout and styling:
- Structure with nested `<table role="presentation" cellpadding="0"
  cellspacing="0" border="0">` — no flexbox, no grid, no floats, no
  position. One centered wrapper table, max-width 600px, single-column
  flow (stacked rows beat side-by-side columns).
- Inline EVERY style on the element it styles. A `<style>` block in
  `<head>` may additionally carry only what can't inline (media queries,
  dark-mode tweaks) — several clients drop it entirely, so the email
  must read correctly from inline styles alone.
- No JavaScript anywhere (universally stripped). No external
  stylesheets. No web fonts — use email-safe stacks (Arial, Helvetica,
  Georgia, Verdana, Tahoma, 'Courier New') with generic fallbacks.
- Build the visual design out of colored table cells, borders, spacer
  cells, and type — not images. There is nowhere to host project
  images from here: a referenced project file will not exist for
  recipients. If imagery is essential, leave a clearly-marked
  placeholder cell with alt text and tell the user to swap in a hosted
  https URL before sending.
- Buttons are "bulletproof": a padded `<td>` with bgcolor and inline
  border-radius, the `<a>` filling it with display:block and inline
  color — never an image, never a styled `<button>`.

Client quirks that matter:
- Outlook (Word engine): give every table/cell explicit widths; set
  line-height with mso-line-height-rule:exactly; wrap Outlook-only
  fixes in `<!--[if mso]> … <![endif]-->` conditionals.
- Gmail clips messages beyond ~100KB of HTML — stay well under.
- Add `<meta name="color-scheme" content="light dark">` and pick colors
  that survive dark-mode inversion (avoid pure `#000/#fff` backgrounds;
  test text on mid-tone fills).

Deliverability and accessibility:
- First element in `<body>`: a hidden preheader span (~85 chars) that
  previews next to the subject line.
- alt text on any image, lang on `<html>`, real `<a href>` links (no
  dead # anchors), and a footer with a plausible unsubscribe line and
  postal address for anything marketing-shaped.

Show the design at 600px; mention in your reply that the file is
send-ready HTML the user can drop into their email tool.

From justinlietz93/Perfect_Prompts, MIT.

More from justinlietz93/Perfect_Prompts

Signals

Stars
23
Forks
1
Open issues
0
Last commit (this folder)
Aug 24, 2026 (2 months ago)
Last release
Aug 22, 2026 (2 months ago)

From GitHub (fetched Oct 24, 2026).

Details

License
MIT
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

Same skill elsewhere

Copies of this SKILL.md published by others; search shows only one of them.

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Cite this page

html-email skill. Agent Mart. https://agentmart.dev/skills/justinlietz93-html-email (last updated 2026-10-24)