email-systems

email-systems is a skill for Claude Code, Codex from travisjneuman/.claude. It costs 55 tokens per session (4,242 once invoked), scanned A, original, MIT.

A guide to sending system-generated email, designing email templates, and improving whether messages reach recipients' inboxes.

In plain words
What is it for?
Use it to connect providers such as Resend, SendGrid, or Amazon SES, create responsive templates, configure SPF, DKIM, and DMARC, and manage bounces or complaints.
Why use it?
It helps handle password resets, receipts, notifications, newsletters, and delivery problems across email services and email clients.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: positional $N argument.

Good fit Use it to connect providers such as Resend, SendGrid, or Amazon SES, create responsive templates, configure SPF, DKIM, and DMARC, and manage bounces or complaints.

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Install with agentmods
npx agentmods add skills/travisjneuman/.claude/email-systems
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add travisjneuman/.claude --skill email-systems
Clone the repo
git clone --depth 1 https://github.com/travisjneuman/.claude

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for email-systems

README.md
[![agentmods](https://agentmods.dev/badge/skills/travisjneuman/.claude/email-systems/github.svg)](https://agentmods.dev/skills/travisjneuman/.claude/email-systems)
Your own site
<a href="https://agentmods.dev/skills/travisjneuman/.claude/email-systems"><img src="https://agentmods.dev/badge/skills/travisjneuman/.claude/email-systems/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for email-systems

Your own site · 80×15
<a href="https://agentmods.dev/skills/travisjneuman/.claude/email-systems"><img src="https://agentmods.dev/badge/skills/travisjneuman/.claude/email-systems.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,242 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00055 $0.04242
Opus 5 $0.00028 $0.02121
Sonnet 5 $0.00011 $0.00848
Haiku 4.5 $0.00006 $0.00424

Measured 8d ago against content hash f722459c0b71, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

email-systems scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/email-systems/SKILL.md · 500 lines

How it starts

The opening of the file, as written. The whole thing — 500 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Email Systems

Overview

This skill covers building reliable email systems for web applications, including transactional email sending, template design, deliverability optimization, and inbox placement. It addresses integration with email service providers (Resend, AWS SES, SendGrid, Postmark), building responsive HTML email templates with React Email and MJML, configuring DNS records for deliverability (SPF, DKIM, DMARC), managing email types (transactional, notification, marketing), queue management, and bounce/complaint handling.

Use this skill when sending welcome emails, password resets, order confirmations, notification digests, marketing campaigns, or any system-generated email. Also use when debugging deliverability issues or migrating between email providers.


Core Principles

  1. Transactional and marketing are different - Transactional emails (password reset, receipt) must arrive instantly and reliably. Marketing emails (newsletter, promo) can be batched and should have unsubscribe links. Never mix them on the same sending domain.
  2. HTML email is not web development - Email clients render HTML from 2004. No flexbox, no grid, no modern CSS. Use tables for layout, inline styles, and test across clients. React Email and MJML abstract this pain.
  3. Deliverability is earned - SPF, DKIM, and DMARC are table stakes, not guarantees. Maintain low bounce rates (< 2%), low complaint rates (< 0.1%), and warm up new sending domains gradually.
  4. Queue everything - Never send email synchronously in a request handler. Queue email sends to avoid blocking user requests and to enable retry on failure.
  5. Test before sending - Use Mailtrap or Ethereal in development, preview in multiple clients (Litmus, Email on Acid), and verify every link works.

Key Patterns

Pattern 1: React Email Templates with Resend

When to use: Building type-safe, component-based email templates with modern DX and reliable delivery.

Implementation:

Read the full file on GitHub · 500 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 500 lines · 55 tokens per session scan A f722459c0b71

Subscribe to this mod's changes

email-systems is a skill published in the GitHub repository travisjneuman/.claude (97 stars, last pushed 6d ago), licensed MIT. It adds 55 tokens to every session and 4,242 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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