An email or distribution list is a group of email addresses along with control software. An electronic message is received and automatically transmitted to all those previously subscripted, without the sender having to send the message to each person separately or maintain a file with all the addressees’ addresses. The only things needed are the name of the list and to send one only message, then the server distributes them.

The main objective of an email list is to allow a rapid and easy communication within a group of people; from each of them to all others. It is not generally restricted to one person sending emails to a group of people but rather for all members to be able to send messages to all members, as well as receiving all messages.

The list has a name (email address, really) and there a determined topic is treated (the name of the list is usually chosen depending on the general idea of the topic it deals with). The users can subscript to the list and, from that moment, the messages sent to the list are received by a server which distributes it to all members of the list. The message distribution, the joins and cancellations of users, etc. are managed by the server’s list software (usually with occasional help of the list’s responsible). Additionally, this software usually presents various additional utilities such as:

• Giving information about the topic, list’s diffusion and its subscripted members.
• Access control to the list (more or less wide): who can and cannot subscribe to the list, who can send messages, etc.
• Automatically file the sent messages in the list and give ways to access them for future reference. Some of the products give a web interface to access the files, even with the capacity of making selective searches in it.

There are several programme packages for the email list management. In the University of Valencia the Majordomo (July 1997, vers. 1.94.3) was installed. Listserv software is the one used since the beginning of 2000, which possesses higher qualities than the former one (regarding efficiency and using ease).