rosa-build/app/mailers/user_mailer.rb

class UserMailer < ActionMailer::Base
  default :from => APP_CONFIG['no-reply-email']

  def new_user_notification(user)
    @user = user
    mail(:to => user.email, :subject => "Регистрация на проекте «#{APP_CONFIG['project_name']}»")
  end
end