This gem is a renamed fork of an existing gem.

MailAllowed is a class you can provide as an interceptor to your Rails app. It ensures only some people are able to receive mails from your app and provides a fallback in case nobody would receive the mail. This can be useful to make sure no accidental emails are sent from your staging environment, but your mails can still be checked.

One way to use it is to set an environment variable MAIL_ALLOWED, check for its existence and use it to instantiate a MailAllowed so that within this environment only those email addresses can have mail sent to them. See below for a code example.


Add this line to your application's Gemfile:

gem 'mail_allowed'

And then execute:

$ bundle

Or install it yourself as:

$ gem install mail_allowed


Specify your allowed as an array of email addresses and register them in an initializer in your Rails app. Optionally specify a fallback address as second argument.

Example Rails app initializer using ENV variables:

require 'mail_allowed'

  allowed_addresses = ENV['MAIL_ALLOWED'].split(',')
  ActionMailer::Base.register_interceptor(, fallback))


After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to


Bug reports and pull requests are welcome on GitHub at


The gem is available as open source under the terms of the MIT License.