If you have to reach out to your users with important information and they signed up with a trash e-mail address you're not like to get the desired attention.This gem checks the e-mail address domain against a blacklist of trash mail providers.

Add this line to your application's Gemfile:

gem 'spam_email'

And then execute:

$ bundle

Or install it yourself as:

$ gem install spam_email

Be advised that the validation checks NOT if a correct e-mail address is given. Validation will pass with empty string/nil value! Checking the input with valid_email or at least checking presence: true is strongly recommendend!

class User < ActiveRecord::Base
  validates :email, presence: true, spam_email: true
end

or specify a custom message with (the gem comes with en/de/fr locales):

validates :email, presence: true, spam_email: { message: "is a blacklisted provider!" }

If you want to add/remove providers you can use an initializer and modify SpamEmail::Blacklist. To disable a provider just set the hash value for the domain to false. You can add new domains by modifing the hash.

You can also check the blacklist directly:

SpamEmail.blacklisted?(email)

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Thanks go to Chris Birner ([email protected]) for the (inital) blacklist and to https://github.com/hallelujah/valid_email for inspiration.