email-best-practices

The reasons email lands in the spam folder, breaks the law, or is unreadable to a blind recipient are all well known by now; this is the collected set of rules for avoiding them.

WHEN TO USE

SCOPE

USE FOR

Diagnose why your emails are landing in spam and fix your domain's authentication records.
Decide whether a given email should be sent as transactional or as a marketing message.
Build a signup flow that captures consent properly before adding someone to a mailing list.
Check a marketing campaign against CAN-SPAM, GDPR, and CASL rules before you send it.
Handle bounces and spam complaints so your sender reputation and list stay healthy.
Make an email's headings, alt text, and color contrast work for screen reader users.

This is a saved copy of the skill's SKILL.md instructions. It may differ from the upstream file or the version you install.

In this document (4)

Email Best Practices

Guidance for building deliverable, compliant, user-friendly emails.

Architecture Overview

[User] → [Email Form] → [Validation] → [Double Opt-In]
                                              ↓
                                    [Consent Recorded]
                                              ↓
[Suppression Check] ←──────────────[Ready to Send]
        ↓
[Idempotent Send + Retry] ──────→ [Email API]
                                       ↓
                              [Webhook Events]
                                       ↓
              ┌────────┬────────┬─────────────┐
              ↓        ↓        ↓             ↓
         Delivered  Bounced  Complained  Opened/Clicked
                       ↓        ↓
              [Suppression List Updated]
                       ↓
              [List Hygiene Jobs]

Quick Reference

Need to...	See
Set up SPF/DKIM/DMARC, fix spam issues	Deliverability
Build password reset, OTP, confirmations	Transactional Emails
Plan which emails your app needs	Transactional Email Catalog
Build newsletter signup, validate emails	Email Capture
Send newsletters, promotions	Marketing Emails
Ensure CAN-SPAM/GDPR/CASL compliance	Compliance
Decide transactional vs marketing	Email Types
Handle retries, idempotency, errors	Sending Reliability
Process delivery events, set up webhooks	Webhooks & Events
Manage bounces, complaints, suppression	List Management
Make emails accessible (screen readers, alt text, contrast)	Accessibility

Start Here

New app? Start with the Catalog to plan which emails your app needs (password reset, verification, etc.), then set up Deliverability (DNS authentication) before sending your first email.

Spam issues? Check Deliverability first—authentication problems are the most common cause. Gmail/Yahoo reject unauthenticated emails.

Marketing emails? Follow this path: Email Capture (collect consent) → Compliance (legal requirements) → Marketing Emails (best practices).

Production-ready sending? Add reliability: Sending Reliability (retry + idempotency) → Webhooks & Events (track delivery) → List Management (handle bounces).

Accessibility? Most emails fail basic accessibility checks. See Accessibility for lang/dir, presentational tables, headings, alt text, <title>, and contrast.

No requirements beyond installing this skill were found.

Listed as free: Connected services may require an account or charge fees.
Installation: One command — usually under 2 minutes.

This skill ships inside the Resend Skills plugin. Listed package contents include an MCP server. Installed components and skill versions may vary by AI tool.

Install just this skill

Run this outside your AI tool, using Node.js 22.20.0 or newer. Skills CLI 1.7.2 skips skill selection; prompts cancel installation without an interactive terminal. If choosing Project when asked about installation scope, open your project's folder before running this.

Install checklist

Check selected tools if a picker appears; Claude Code may be unchecked under Additional agents. ↑/↓ moves, Space toggles selections, Enter confirms.
Without a tool picker, check Installing to: for your intended tool. Stop if it names a different tool.
If asked, choose Symlink (Recommended) for shared files or Copy to all agents for separate copies; review the summary before confirming installation.
Install the find-skills skill? defaults to Yes, adding another skill for all projects. Choose No if you don't want that extra installation.

Skills CLI 1.7.2 sends install data to skills.sh by default, including the source, skill names, target tools and file details; GitHub sources are reported only when GitHub confirms the repository is public, while other remote sources can also be reported. Confirmed-public GitHub sources also trigger a security-audit request. Before installing, set the environment variable DO_NOT_TRACK=1 or DISABLE_TELEMETRY=1 to disable both.

npx skills add resend/resend-skills --skill "email-best-practices" --full-depth

After installing for Claude Code, open it in the installation project if you chose Project; Global makes the skill available across projects on this computer. Once Claude Code loads the skill, its description helps Claude decide when to use it.

If installation created a top-level skills folder that did not exist when your Claude Code session started, run /reload-skills in that session. Run it again after later changes in that folder.

Install the whole plugin

This route installs the Resend Skills plugin package selected for your AI tool.

PLUGIN MARKETPLACE

Add the marketplace, then install the plugin

Typed inside the agent's own prompt, not in a terminal. The marketplace is called resend-skills, which is the part after the @.

01

/plugin marketplace add resend/resend-skills

02
```
/plugin install resend@resend-skills
```

Open plugin page ↗

What's inside

Files included with this skill.

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The repository is licensed under MIT — use, modification, and redistribution are allowed under that license’s terms.

View the repository’s license file on GitHub →