MailInterceptor

This gem intercepts and forwards email to a forwarding address in a non-production environment. It also allows to not intercept certain emails so that testing of emails is easier in development/staging environment.

Installation

Add this line to your application's Gemfile:

# There is no need to include this gem for production or for test environment
gem 'mail_interceptor', group: [:development, :staging]

Usage

# config/initializer/mail_interceptor.rb

options = { forward_emails_to: 'intercepted_emails@domain.com',
            deliver_emails_to: ["@wheel.com"] }

interceptor = MailInterceptor::Interceptor.new(options)

unless (Rails.env.test? || Rails.env.production?)
  ActionMailer::Base.register_interceptor(interceptor)
end

Do not use this feature in test mode so that in your tests you can test against real recipients of the email.

deliver_emails_to

Passing deliver_emails_to is optional. If no "deliver_emails_to" is passed then all emails will be intercepted and forwarded in non-production environment.

Let's say that you want to actually deliver all emails having the pattern "@BigBinary.com". Here is how it can be accomplished.

MailInterceptor::Interceptor.new({ forward_emails_to: 'intercepted_emails@domain.com',
                                   deliver_emails_to: ["@bigbinary.com"] })

If you want the emails to be delivered only if the email address is qa@bigbinary.com then that can be done too.

MailInterceptor::Interceptor.new({ forward_emails_to: 'intercepted_emails@domain.com',
                                   deliver_emails_to: ["qa@bigbinary.com"] })

Now only qa@bigbinary.com will get its emails delivered and all other emails will be intercepted and forwarded.

The regular expression is matched without case sensitive. So you can mix lowercase and uppercase and it won't matter.

forward_emails_to

This is a required field.

It can take a single email or an array of emails.

MailInterceptor::Interceptor.new({ forward_emails_to: 'intercepted_emails@bigbinary.com' })

It can also take an array of emails in which case emails are forwarded to each of those emails in the array.

MailInterceptor::Interceptor.new({ forward_emails_to: ['intercepted_emails@bigbinary.com',
                                                       'qa@bigbinary.com' })

Custom environment

By default all emails sent in non production environment are intercepted. However you can control this behavior by passing env as the key. It accepts any ruby objects which responds to intercept? method. If the result of that method is true then emails are intercepted otherwise emails are not intercepted.

Below is an example of how to pass a custom ruby object as value for env key.

Besides method intercept? method name is needed if you have provided subject_prefix. This name will be appended to the subject_prefix to produce something like [WHEEL STAGING] Forgot password. In this case STAGING came form name.

class MyEnv
  def name
    ENV["ENVIRONMENT_NAME"]
  end

  def intercept?
    ENV["INTERCEPT_MAIL"] == '1'
  end
end

MailInterceptor::Interceptor.new({ env: MyEnv.new,
                                   forward_emails_to: ['intercepted_emails@bigbinary.com',
                                   'qa@bigbinary.com' })