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Mailing lists - General introduction

What is a mailing list?

A mailing list is a distribution list allowing a group of subscribers to automatically receive by email all messages sent to the list: every message sent to the list by a subscriber is received by all the other subscribers. When subscribed to a mailing list, it is possible to send messages, to reply to them or to read them without contributing (i.e. to "lurk").

Special cases:

  • It is sometimes possible to send messages to a mailing lit without having subscribed to it. However, you need to be subscribed to a list to receive its messages.
  • It is sometimes impossible to send messages to the list even though you are actually subscribed to it: it is the case for announcement lists, which are used to transmit information from a unique sender to a large number of recipients.

Interest of mailing lists

People subscribe to a mailing list (sometimes abbreviated in ML) to be informed about a particular topic and to take part in exchanges about it. Examples are:

  • mailing list for all the employees of a company;
  • mailing list reserved to the participants in a project;
  • mailing list dedicated to a class of students;
  • mailing list about the latest news in computer security;
  • mailing list of mutual aid between handymen;
  • mailing list restricted to a family and dedicated to the organization of large family gatherings;
  • and so on!

Types of mailing lists

There are thousands of mailing lists of all kinds on the Internet: public or private, free or not, with subscription subject to conditions or not, etc. Those lists may have from a dozen up to several thousand members.

According to the way they work, we can distinguish between two types of lists:

  • Announcements lists allow subscribers to receive messages without being allowed to post some themselves. In fact, those messages are newsletters: electronic magazines, daily services (daily horoscope, daily weather report, daily security alert, etc.), update notices about a website, etc. With this type of mailing list, the information flows from a unique sender to a large number of recipients.
  • Discussion lists allow all subscribers to take part in exchanges. Those lists can be moderated or not:
    • In a moderated discussion list, messages are transmitted to all subscribers after approval by one of the list moderators. Moderation is a token of quality for the list. For example, it ensures that subscribers will not receive off-topic messages, unsolicited commercial messages (spams), messages containing large attachments, etc.
    • In a non moderated discussion list, messages are transmitted to all subscribers as soon as the mailing list management robot receives them.


Once subscribed to a mailing list service, you can:

How the mailing list service works: roles and responsibilities

A mailing list service involves four types of roles:

  • listmaster;
  • owner;
  • moderator;
  • subscriber.

It is possible to have several roles at once (for example, you can be an owner and a moderator of a list and be subscribed to several others).


Listmasters are in charge of the management of the mailing list service. Their duties:

  • manage the mailing list server (deployment, maintenance, etc.);
  • define the general orientations of the mailing list service:
    • who will be allowed to ask for the creation of a new list,
    • which options will be available to manage lists (scenario definition),
    • what the default files will contain (creation of templates),
    • what will the mailing list web interface look like;
  • set the way the mailing list service should be used and document those rules through providing charters to subscribers, moderators and owners;
  • approve of requests of mailing list creations;
  • temporarily replace list owners when necessary; on the other hand, listmasters are not supposed to take the place of moderators.

List owners and moderators can turn to listmasters when they face a problem not dealt with by the documentation or for any comment. However, in order not to flood listmasters with messages, it is recommended that subscribers rather turn to list owners.


The list owner is generally its creator or, failing him/her, the person who requested the list creation or who became responsible for it. His/her role:

A list can have several owners. However, the 'Privileged' profile is reserved to the list's creator; other owners have a 'Normal' profile, which has fewer prerogatives.


Moderators are appointed by the list owner. They are in charge of controlling the relevancy of the messages sent to the list: after reading them, they choose to accept or to reject them . Moderation occurs before the message is actually sent to subscribers. Rejection of a message is possibly followed by a notice to the sender in order to explain the reason for that rejection.

A list can have one or several moderators; generally, the list owner is also a moderator.

This concerns only moderated lists.

Regulatory framework

The use of a mailing list service means respecting a number of rules:

  • In most mailing list services, subscribers receive a 'List subscribers charter' on subscription. Then they are obliged to respect all the rules contained in that charter.
  • If available, list owners and moderators have to conform to the Owner and moderator charter.
  • The use of mailing lists naturally means respecting the rules of good practices as regards email (the "Netiquette").

To know more, refer to the section dedicated to good practices for subscribers and to the section about good practices for owners and moderators.

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