email-best-practices

配信可能でコンプライアンスに準拠したユーザーフレンドリーなメールシステムを構築するための包括的なガイダンス。認証設定（SPF/DKIM/DMARC）、スパムトラブルシューティング、メールがスパムフォルダに入らないようにするための配信性のベストプラクティスをカバー。トランザクションメール（パスワードリセット、OTP、確認メール）や、適切な同意ワークフローを備えたマ

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.