gistfile1.txt

#/app/mailers/user_mailer.rb
def welcome (current_user)
  unless current_user.nil?
    mail(
      :from => "myid@gmail.com",
      :to => current_user.email,
      :subject => "Thank you for signing"
    )
  else
    mail(
      :from => "myid@gmail.com",
      :to => "test@mail.com",
      :subject => "Thank you for signing"
    )
  end
end

gistfile2.txt

#/app/controllers/registration_controller.rb

def create
  build_resource

  if resource.valid?
    begin
      resource.transaction do
        resource.save!
      end
    UserMailer.welcome(resource).deliver
    flash[:notice] = "Successfully registered"
    sign_in(resource)
    respond_with resource, :location => after_sign_up_path_for(resource)
  rescue ActiveRecord::RecordInvalid => invalid
    flash[:notice] = " Please try again"
    clean_up_passwords resource
    respond_with resource
  end
else
  clean_up_passwords resource
  respond_with resource
end

end