Resumen
The usefulness of electronic mail (e-mail) is seriously threatened by the commercialization of the Internet because it is easier than ever to collect address lists and cheaper than ever to mass-distribute messages termed as "junk mails." A novel technique called "email channels," which is build on and systemizes these ideas in the domain of e-mail communication is presented. It solves the problems involved in unlisted numbers and physical mail addresses, as well as additional problems introduced by the nature of e-mail, providing a lightweight, fine-grained access-control method. Channels and list servers together can be used to implement private mailing lists, allowing groups to confer without requiring that they all have direct channels to each other, while prohibiting outsiders from sending to the group. Channelized e-mail can also enhance the effectiveness of email agents and filters by providing categorization based on which correspondents are presumed to know which channels. A personal channel agent (PCA) is designed and implemented that shields the user from most of these complexities raised by using the email channels, including security, ease of use, and administration. Channels approach exploits the idea of concealing the users address, providing a simple yet effective way to avoid unwanted e-mail. PCA can essentially automate all the operations necessary to manage the complexities introduced by channels, so routine daily use is transparent to e-mail users