Mailing list

A mailing list is a collection of names and addresses used by an individual
or an organization to send material to multiple recipients. The term is
often extended to include the people subscribed to such a list, so the group
of subscribers are referred to as "the mailing list", or simply "the list".

At least two quite different types of mailing lists can be defined: the
first one is closer to the literal sense, where a "mailing list" of people
is used as a recipient for newsletters, periodicals or advertising.
Traditionally this was done through the postal system, but with the rise of
e-mail, the electronic mailing list became popular. Such a list is usually
unidirectional, with a list owner sending mail and subscribers receiving it.

The second type is sometimes more accurately called a "discussion list": a
subcriber uses the mailing list to send messages to all the other
subscribers, who may answer in similar fashion. Thus actual discussion and
information exchanges can happen. Mailing lists of this type are usually
topic-oriented (for example, politics, scientific discussion, joke
contests), even if the topic can range from extremely narrow to "whatever
you think could interest us". In this they are similar to Usenet newsgroups,
and share the same aversion to off-topic messages.

Some mailing lists are open to anyone who want to join them, while others
require an approval from the list owner before one can join. In even more
strict mailing list, every message must be approved by a moderator before
being sent to the rest of the subscribers. Moderator approval is usually
employed to keep a high average quality of posts and weed out spam. While
sometimes people see those restrictions as contrary to freedom of speech,
this position is quite unrealistic: a different mailing list with more open
rules can be started by anyone.