In meiner ROR-App versuche ich, Bestätigungs-E-Mails an meine registrierten Benutzer zu senden, wenn diese sich anmelden. Meine Website befindet sich derzeit auf localhost. Ich erhalte diesen Fehler:

"undefined method `recipients' for #<UserMailer:0x3d841a0>"

Hier ist mein Code;

development.rb

config.action_mailer.delivery_method = :smtp
config.action_mailer.default_url_options = { :host => "localhost:3000"}
config.action_mailer.smtp_settings = {
      :address      => "smtp.gmail.com",
      :port          => "587",
      :authentication => :login,
      :user_name      => "[email protected]",
      :password       => "myrealpassword"
}  

Users_controller.rb

def new
  UserMailer.registration_confirmation(@user).deliver
end

def create
  @user = User.new(params[:user])
  if @user.save
    UserMailer.registration_confirmation(@user).deliver
    sign_in @user
    flash[:success] = "Welcome!"
    redirect_to @user
  else
    render 'new'
  end
end

user_mailer.rb

class UserMailer < ActionMailer::Base   
  def registration_confirmation(user)
    recipients   user.email
    from         "[email protected]"
    subject      "Thank you for registration"
    body         :user => user  
  end
end