Почему возникает ошибка Net::SMTPAuthenticationError?

Net::SMTPAuthenticationError (534-5.7.14 <https://accounts.google.com/ContinueSignIn?sarp=1&scc=1&plt=AKgnsbvm6
):
  app/controllers/pages_controller.rb:11:in `send_email'

def send_email
        @client = Client.new(user_params)
        if @client.save
            AppMailer.welcome_email(@client).deliver
        end
    end

config.action_mailer.delivery_method = :smtp
  config.action_mailer.raise_delivery_errors = true
  ActionMailer::Base.smtp_settings = {
    :address        => 'smtp.gmail.com',
    :domain         => 'gmail.com',
    :port           => 587,
    :user_name      => 'мой_майл@gmail.com',
    :password       => 'пароль',
    :authentication => :plain,
    :enable_starttls_auto => true
  }

Sent mail to Куда@mail.ru (1407.7ms)
Date: Sat, 11 Oct 2014 21:10:53 +0400
From: Откуда@gmail.com
To: Куда@mail.ru
Message-ID: <5439649d3f738_167b261bf78745fb@SkyMint.mail>
Subject: =?UTF-8?Q?=D0=97=D0=B0=D0=BA=D0=B0=D0=B7_45?=
Mime-Version: 1.0
Content-Type: text/html;
 charset=UTF-8
Content-Transfer-Encoding: base64