Email Best Practices

A comprehensive reference for developers building email features, covering everything from DNS authentication (SPF/DKIM/DMARC) to compliance (CAN-SPAM, GDPR, CASL). Created by Resend, it includes an architecture diagram showing the full flow from form capture through double opt-in to webhook handling, plus a decision matrix that routes you to the right guide based on your problem. The transactional email catalog is especially useful if you're starting fresh and need to figure out which emails your app actually needs. It separates transactional from marketing concerns clearly, which matters because mixing them up causes deliverability problems. The reliability section on retries and idempotency will save you from duplicate sends.

skills.sh installs: 14.2K
GitHub stars: 211
last updated: Aug 21, 2026

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Install

$ npx -y skills add resend/resend-skills --skill email-best-practices --agent claude-code

Installs into .claude/skills of the current project.

Files

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]