app/mailers/order_mailer.rb

order_mailer.rb

class OrderMailer < ActionMailer::Base
  default from: "[email protected]"

  def notify_order_placed(order)
    
    @order = order
    @user = order.user
    @order_items = @order.items
    @order_info = @order.info


    mail(:to => @user.email , :subject => " [ArtStore] 感謝您完成本次的下單，以下是您這次購物明細 #{order.token}")
  end

end