Send all ActionMailer emails to a specific email adress

staging.rb

# Want your Rails app to send all ActionMailer emails 
# to a specific email adress instead of sending it 
# to the world (e.g. in the staging environment)?
#
# Put this into e.g. config/environments/staging.rb
  
config.after_initialize do
  module ::ActionMailer
    class Base
      class_eval do
        def deliver_with_overwritten_recipients!(mail = @mail)
          mail['cc'], mail['bcc'] = nil, nil
          mail['to'] = "[email protected]" # All emails will go here
          deliver_without_overwritten_recipients!(mail)
        end
        alias_method_chain :deliver!, :overwritten_recipients
      end
    end
  end
end