A method for using a unique identifier in the email address format (generalized email address) to prevent spam email from reaching an email system is described. According to one embodiment of the invention, a method for sending and receiving emails in the email system is provided. The method includes using any valid regular email address to send an email to a group of recipients by a sender of the system. If recipient's email address is not in the system, the recipient receives a request email via regular email service for joining the system. After joining the system, the recipient needs to make a contact connection with the sender for retrieving the email by using generalized email address. The spam email cannot reach the system that based on generalized email address.