A way of having a group discussion by electronic mail. Also used to distribute announcements to a large number of people. A mailing list is very much like a conference on a bulletin board system, except the conversation comes to you in your e-mail box. Each time you or any member of the list posts a reply to the conversation, it is distributed to the e-mail box of every member of the list. All of this traffic is automated and managed by programs called mailing list managers (MLM's) or mail servers. The two most frequently used programs are Listserv and Majordomo.

Mailing lists are the most basic form of Internet conferencing. They can be public or private and, unlike Usenet newsgroups, which require additional software to run, all you need to participate is an e-mail address.

A mailing list is said to be "unmoderated" if all of the messages sent to the list are automatically forwarded to each member of the list. In a "moderated" list, all messages are sent first to a list moderator, who makes decisions about which postings will or will not be sent to everyone on the list.

If many people are on a mailing list, the traffic in your e-mail box can be overwhelming. One way to deal with this is to subscribe to the "digest" version of the list (not all mailing lists have digest versions). In a digest version, postings are collected into a single file and distributed to the list on a regular basis (usually daily). In this way you receive only one big file at regular intervals rather than hundreds of small ones everyday.

You join a mailing list by subscribing to it - also termed Opting-In or Opt-in Direct Email. This doesn't mean you have to pay money, it just means you are asking to have your e-mail address added to the distribution list. To get off the mailing list, you have to unsubscribe from the list. You do both by sending an e-mail message to the list administrator with the following in the body of your message:

subscribe name-of-list your e-mail address
or
unsubscribe name-of-list your e-mail address

The exact way of doing this varies a little from list to list. It's best to request information about the list first and that will tell you exactly what you need to do. Once you've subscribed to a list you will receive an e-mail message with details about how the list works and how to unsubscribe.