Test your ActionMailer and Mailer messages in Capybara

Rails performance tests (removed from core in Rails 4.0)

The Postmark Rails Gem is a drop-in plug-in for ActionMailer to send emails via Postmark, an email delivery service for web apps.

Gem to extend ActionMailer with SendGrid API support

Easy SQL based report generation with the ability to accept request parameters and render multiple formats.

Best practice is to send text/plain && text/html markdown works great for both, so why write your templates twices?

An adapter for using Mailgun with Rails and Action Mailer

Ruby wrapper for Mailjet's v3 API

This gem instruments your Ruby on Rails application using InfluxDB.

Database-backed Rails error subscriber

Mail safe provides a safety net while you're developing an application that uses ActionMailer. It keeps emails from escaping into the wild. Once you've installed and configured this gem, you can rest assure that your app won't send ...

Making HTML emails a little less painful. Writes css inline and corrects image urls.

A delivery method to send your notifications via email using ActionMailer.

Implement texter classes for sending SMS messages in similar way to how e-mails are sent with ActionMailer-based mailers. Take advantage of e-mail proxying and enhanced phone number parsing, among others.

A set of patches for mikel's mail gem. With this, you can easily send and receive mails with ISO-2022-JP enconding (so-called 'JIS-CODE').

The Let's Encrypt certificate manager for rails

Asynchronous mail delivery using sidekiq

Super simple capistrano deployment notifications.

New generation ruby client for IronWorker

Specify a domain (or set of domains, or magic word in email address) email is allowed to go to, and email to all other domains is silently dropped. Useful for testing and staging environments.