Agent skill

Mailtrap Email Integration

Guides agents through integrating transactional email sending via Mailtrap's Email API, including sandbox testing, domain verification, and API authentication.

MITAuto-check passedBackend & APIs

Install Mailtrap Email Integration

skills CLI

$ npx skills add affaan-m/ECC --skill mailtrap-email-integration -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install affaan-m/ECC mailtrap-email-integration --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/affaan-m/ECC.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/mailtrap-email-integration .claude/skills/mailtrap-email-integration && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "mailtrap-email-integration" agent skill from https://github.com/affaan-m/ECC/tree/main/skills/mailtrap-email-integration into .claude/skills/mailtrap-email-integration/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mailtrap-email-integration", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/affaan-m/ECC/tree/main/skills/mailtrap-email-integration

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add affaan-m/ECC --skill mailtrap-email-integration -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install affaan-m/ECC mailtrap-email-integration --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/affaan-m/ECC.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/mailtrap-email-integration .agents/skills/mailtrap-email-integration && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "mailtrap-email-integration" agent skill from https://github.com/affaan-m/ECC/tree/main/skills/mailtrap-email-integration into .agents/skills/mailtrap-email-integration/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mailtrap-email-integration", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add affaan-m/ECC --skill mailtrap-email-integration -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install affaan-m/ECC mailtrap-email-integration --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/affaan-m/ECC.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/mailtrap-email-integration .cursor/skills/mailtrap-email-integration && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "mailtrap-email-integration" agent skill from https://github.com/affaan-m/ECC/tree/main/skills/mailtrap-email-integration into .cursor/skills/mailtrap-email-integration/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mailtrap-email-integration", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/affaan-m/ECC.git --path skills/mailtrap-email-integration

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add affaan-m/ECC --skill mailtrap-email-integration -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install affaan-m/ECC mailtrap-email-integration --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/affaan-m/ECC.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/mailtrap-email-integration .gemini/skills/mailtrap-email-integration && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "mailtrap-email-integration" agent skill from https://github.com/affaan-m/ECC/tree/main/skills/mailtrap-email-integration into .gemini/skills/mailtrap-email-integration/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mailtrap-email-integration", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install affaan-m/ECC mailtrap-email-integration

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add affaan-m/ECC --skill mailtrap-email-integration -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/affaan-m/ECC.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/mailtrap-email-integration .github/skills/mailtrap-email-integration && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "mailtrap-email-integration" agent skill from https://github.com/affaan-m/ECC/tree/main/skills/mailtrap-email-integration into .github/skills/mailtrap-email-integration/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mailtrap-email-integration", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add affaan-m/ECC --skill mailtrap-email-integration -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install affaan-m/ECC mailtrap-email-integration --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/affaan-m/ECC.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/mailtrap-email-integration .opencode/skills/mailtrap-email-integration && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "mailtrap-email-integration" agent skill from https://github.com/affaan-m/ECC/tree/main/skills/mailtrap-email-integration into .opencode/skills/mailtrap-email-integration/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mailtrap-email-integration", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: mailtrap-email-integration
GitHub stars: 277k
Used in: 1 other repo
Token cost: ~955 tokens
SKILL.md length: 321 words
Files: 1
Skills in repo: 683
Repo updated: Oct 11, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Guides agents through integrating transactional email sending via Mailtrap's Email API, including sandbox testing, domain verification, and API authentication.

Implementing email-sending features
SKILL.md covers When to Activate, Core Concepts, Code Examples and Anti-Patterns, plus 2 more sections
Reaches send.api.mailtrap.io and sandbox.api.mailtrap.io; needs MAILTRAP_API_TOKEN
Debugging delivery issues

What it does

Mailtrap Email Integration is an agent skill from affaan-m/ECC. Guides agents through integrating transactional email sending via Mailtrap's Email API, including sandbox testing, domain verification, and API authentication. Use when implementing email-sending features, debugging delivery issues, or setting up safe dev/staging email testing.

Its SKILL.md is about 960 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Backend & APIs, covering Transactional email. The repository describes itself as: The agent harness performance optimization system. Skills, instincts, memory, security, and research-first development for Claude Code, Codex, Opencode, Cursor and beyond. The licence is MIT.

When your agent uses it

Implementing email-sending features
Debugging delivery issues
Setting up safe dev/staging email testing

Example prompts

“Use the mailtrap-email-integration skill to guide agents through integrating transactional email sending via Mailtrap's Email API, including sandbox…”
“/mailtrap-email-integration”

Requirements

A credential in MAILTRAP_API_TOKEN

What it can do on your machine

Read from SKILL.md and the folder at commit 2d515e4. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are typescript).
From the folder's file list and the shell code blocks in SKILL.md.
Network
Hosts in commands or code, which the agent is likely to contact:
- send.api.mailtrap.io
- sandbox.api.mailtrap.io
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names these keys or tokens, usually read from environment variables:
- MAILTRAP_API_TOKEN
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Mailtrap Email Integration loads about 955 tokens when it runs. Until then it costs about 76 tokens; SKILL.md has 321 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~76
When it runs · the whole SKILL.md, loaded when a task matches: ~955

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from affaan-m/ECC at commit 2d515e4, republished under its MIT licence (© affaan-m). 321 words, ~955 tokens.

Download SKILL.mdSave it as .claude/skills/mailtrap-email-integration/SKILL.md (or your agent's skills folder).

name: mailtrap-email-integration
description: Guides agents through integrating transactional email sending via Mailtrap's Email API, including sandbox testing, domain verification, and API authentication. Use when implementing email-sending features, debugging delivery issues, or setting up safe dev/staging email testing.
origin: ECC

Mailtrap Email Integration

Patterns for adding transactional email sending to an application using Mailtrap's Email API and Sandbox, covering authentication, environment separation, and common delivery pitfalls.

When to Activate

Implementing a "send email" feature (signup confirmation, password reset, notifications, receipts)
Debugging why emails aren't arriving in dev/staging
Setting up a project's first email-sending integration
Reviewing code that calls an email API directly without sandbox separation

Core Concepts

Sandbox vs. Production separation. Mailtrap provides a Sandbox API that captures emails without delivering them, used for dev/staging so test emails never reach real inboxes. Production sending uses a separate, verified-domain endpoint. Never point a dev environment at the production sending endpoint.

Authentication. Requests use a Bearer token in the Authorization header. Tokens are scoped per project; sandbox and production typically use different tokens.

Domain verification. Production sending requires verifying a sending domain via DNS records (SPF, DKIM, DMARC) before Mailtrap will deliver to real recipients. Skipping this causes silent delivery failures or spam-folder placement.

Code Examples

typescript

// Sending via Mailtrap's Email API (production)
async function sendEmail(to: string, subject: string, html: string) {
  const response = await fetch("https://send.api.mailtrap.io/api/send", {
    method: "POST",
    headers: {
      "Authorization": `Bearer ${process.env.MAILTRAP_API_TOKEN}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      from: { email: "no-reply@yourverifieddomain.com", name: "Your App" },
      to: [{ email: to }],
      subject,
      html,
    }),
  });

  if (!response.ok) {
    throw new Error(`Email send failed: ${response.status}`);
  }
  return response.json();
}

typescript

// Same call, routed to Sandbox in non-production environments
const MAILTRAP_ENDPOINT = process.env.NODE_ENV === "production"
  ? "https://send.api.mailtrap.io/api/send"
  : `https://sandbox.api.mailtrap.io/api/send/${process.env.MAILTRAP_INBOX_ID}`;

Anti-Patterns

Anti-Pattern	Why It's a Problem	Instead
Using the production sending endpoint in dev/test	Real test emails reach real inboxes, risking spam complaints and leaked test data	Route non-production environments to the Sandbox endpoint
Hardcoding API tokens in source	Credential leak risk if committed to version control	Load tokens from environment variables / secrets manager
Sending before domain verification completes	Emails silently fail or land in spam	Verify SPF/DKIM/DMARC records before enabling production sending
No retry/error handling on send failures	Silent notification failures (e.g., user never gets password reset email)	Check response status, log failures, surface actionable errors

Best Practices

Keep sandbox and production tokens in separate environment variables, never share one token across environments
Verify sending domain DNS records before any production launch involving email
Log delivery failures with enough context to debug (recipient, template, timestamp, response code)
Treat email sending as a fallible network call: wrap in try/catch, never assume success

api-and-interface-design, security-and-hardening, ci-cd-and-automation

Files

Just SKILL.md in skills/mailtrap-email-integration of affaan-m/ECC.

Open the folder on GitHubat commit 2d515e4

Used in 1 other repository

We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in affaan-m/ECC, which our catalogue first saw on October 7, 2026.

templetongroup/radiantskills/mailtrap-email-integration

Compare with similar skills

Mailtrap Email Integration next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

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Email Best Practicesviclafouch/meme-studio	110	7 repos	~787	Automated safety check: Pass	None	6 mo ago
React Emailviclafouch/meme-studio	110	2 repos	~3.6k	Automated safety check: Pass	MIT	6 mo ago
Pinme Emailglitternetwork/pinme	3.8k	—	~1.2k	Automated safety check: Pass	MIT	29 days ago

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Questions about Mailtrap Email Integration

What does Mailtrap Email Integration do?

Guides agents through integrating transactional email sending via Mailtrap's Email API, including sandbox testing, domain verification, and API authentication. Mailtrap Email Integration is an agent skill from affaan-m/ECC. Guides agents through integrating transactional email sending via Mailtrap's Email API, including sandbox testing, domain verification, and API authentication.

When should I use Mailtrap Email Integration?

Mailtrap Email Integration fits situations like: implementing email-sending features; debugging delivery issues; setting up safe dev/staging email testing.

How do I install Mailtrap Email Integration in Claude Code?

Run `npx skills add affaan-m/ECC --skill mailtrap-email-integration -a claude-code`. Or copy the skill folder (skills/mailtrap-email-integration in affaan-m/ECC) into .claude/skills/mailtrap-email-integration in your project. Claude Code loads it when a task matches its description.

How do I install Mailtrap Email Integration in Codex?

Run `npx skills add affaan-m/ECC --skill mailtrap-email-integration -a codex`. Or copy the skill folder (skills/mailtrap-email-integration in affaan-m/ECC) into .agents/skills/mailtrap-email-integration in your project. Codex loads it when a task matches its description.

Can I use Mailtrap Email Integration in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add affaan-m/ECC --skill mailtrap-email-integration -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/mailtrap-email-integration, .gemini/skills/mailtrap-email-integration, .github/skills/mailtrap-email-integration and .opencode/skills/mailtrap-email-integration in your project.

What does Mailtrap Email Integration need to run?

Going by SKILL.md and its folder, Mailtrap Email Integration needs credentials named MAILTRAP_API_TOKEN. Our summary lists: A credential in MAILTRAP_API_TOKEN.

Does Mailtrap Email Integration access the network?

SKILL.md names 2 domains. In commands or code: send.api.mailtrap.io and sandbox.api.mailtrap.io; the agent is likely to contact these when it follows the instructions. This is read from the text; nothing was executed.

Is Mailtrap Email Integration safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Mailtrap Email Integration use?

Mailtrap Email Integration is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Mailtrap Email Integration use?

About 955 tokens (SKILL.md is roughly 3.8k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Mailtrap Email Integration?

Skills that share tags, products or a category with Mailtrap Email Integration: Stripe Projects (fossasia/eventyay, 1.7k stars), WooCommerce Email Editor Development (woocommerce/woocommerce, 11k stars), Email Best Practices (viclafouch/meme-studio, 110 stars) and React Email (viclafouch/meme-studio, 110 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Mailtrap Email Integration?

affaan-m (a GitHub user) maintains it in affaan-m/ECC, which has 276,673 GitHub stars. The repository holds 683 skills in this directory. The repository was last updated on October 11, 2026.

Source: affaan-m/ECC on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Mailtrap Email Integration

Install Mailtrap Email Integration

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Mailtrap Email Integration

When to Activate

Core Concepts

Code Examples

Anti-Patterns

Best Practices

Files

Used in 1 other repository

Compare with similar skills

Similar skills

Stripe Projects

WooCommerce Email Editor Development

Email Best Practices

React Email

Pinme Email

Email Deliverability Audit

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Questions about Mailtrap Email Integration

Install Mailtrap Email Integration

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Mailtrap Email Integration

When to Activate

Core Concepts

Code Examples

Anti-Patterns

Best Practices

Related Skills

Files

Used in 1 other repository

Compare with similar skills

Similar skills

More from affaan-m/ECC

Related

Questions about Mailtrap Email Integration