actionmailer-baseline

What problem does it solve?

AI coding agents frequently implement ActionMailer incorrectly for Rails applications, leading to blocked request threads from synchronous email sends, duplicate emails on job retries, poor sender reputation from unhandled bounces, and broken email templates that fail spam checks. This skill provides senior Rails developer-approved patterns to eliminate these common production failures.

Core Features & Use Cases

• Async Default Delivery: Enforces deliver_later for all user-facing request paths to avoid blocking user responses, with clear guidance on when synchronous deliver_now is appropriate.
• Production Vendor Integration: Pre-configured setup for Postmark, SendGrid, AWS SES, and Mailgun with decision matrices to match your app's scale and compliance needs.
• Bounce & Complaint Handling: Webhook routing and mailer interceptor patterns to suppress sends to undeliverable addresses and protect your domain's sender reputation.
• Idempotent Transactional Sends: Guard patterns to prevent duplicate password reset and welcome emails on job retries, using sent-at tracking columns.
• Development Tooling: Mailer previews and Letter Opener configuration to inspect rendered emails locally without sending real messages.
• Test Coverage: RSpec patterns for mailer specs, job specs, and request specs using have_enqueued_mail matchers to validate email behavior.
• i18n Support: Locale-aware subject and body rendering for multi-language user bases. Use case: A SaaS app sending password reset emails can use this skill to implement async delivery, bounce handling, and idempotent tokens to avoid duplicate resets and maintain deliverability.

Quick Start

Use the actionmailer-baseline skill to configure async transactional email delivery with bounce handling and mailer previews for your Rails 8 application.