Mailing lists - general introduction

From 28 November 2013: If you are completing any of the tasks below from outside the University, you will need to connect to the VPN first.

What is a mailing list?

A mailing list (ML) is a distribution list that lets a group of subscribers automatically receive all email messages sent to the list by a subscriber.  When subscribed to a mailing list you can send, reply to and read messages, even if you do not otherwise contribute.

People generally subscribe to a mailing list because they are interested in a specific topic and want to be kept informed and/ or take part in information exchange. 

Examples of mailing lists could be:

  • For everyone in a specific department or faculty
  • For individual project teams
  • For students on a specific course of study
  • For those whose job relies on having the latest news about computer security issues

Types of mailing lists

According to the way they work, there are two distinguishable types of lists (though there are several variants of each available in Sympa):

  • Announcements lists: these let subscribers receive messages without being allowed to post messages and tend to include newsletters, electronic magazines, daily weather reports, daily security alerts, update notices, and so on.
  • Discussion lists: these let all subscribers take part in exchanges and can be moderated or non-moderated.

The difference between moderated and non-moderated lists is as follows:

  • In a moderated list, messages are transmitted to all subscribers after approval by one of the assigned moderators.  The moderation process constitutes a token of quality assurance for the list by, ensuring that subscribers do not receive off-topic messages, unsolicited spam, messages containing large attachments, and so on.
  • In a non moderated list, messages are transmitted to all subscribers as soon as the mailing list management robot receives them.

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Roles and responsibilities

A mailing list service involves four types of roles - listmaster, list owner, moderator and subscriber - and you can have several roles at once (for example, you can be an owner and a moderator of a list and be subscribed to several other lists)


The listmaster is in charge of the management of the mailing list service and their role is:

  • To manage the mailing list server (issues about deployment, maintenance, etc.)
  • To decide who will be allowed to ask for the creation of a new list, which options will be available to manage lists, what the default files will contain, creation of templates, what will the mailing list web interface will look like and so on
  • To set the way the mailing list service should be used and document those rules through providing charters to subscribers, moderators and owners
  • To approve of requests of mailing list creations
  • To temporarily replace list owners when necessary (though the listmaster is not supposed to take the place of moderators)

Please note: list owners and moderators can turn to the listmaster when they face a problem not dealt with by the documentation.  In the same situation, subscribers should turn to list owners, not the listmaster.

List owner

The list owner is generally its creator (or the person who requested the list creation) and their role is:

  • To define the way the list will be used
  • To write a list charter for subscribers
  • To appoint one or more moderators
  • To manage subscriptions
  • To decide whether it is relevant to put a shared document web space at the subscribers' disposal
  • To answer questions from subscribers and potential subscribers about the list

Please note: a list can have several owners but the Privileged profile is reserved to the list's creator and other owners will have a Normal profile, which has fewer responsibilities.


Moderators are appointed by the list owner and are in charge of ensuring the relevancy of messages sent to the list.  After reading all messages, moderators can decide to accept or to reject them.  Rejection of a message may be followed by a notice to the sender to explain the reason for rejection.  A list can have one or more moderators and, generally, the list owner is also a moderator.

Please note: in a non-moderated list, there is no moderation role.

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Regulatory framework

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

  • In most mailing list services, subscribers receive a Subscribers charter on subscription and 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 means respecting the rules of good practices as regards email (Netiquette).

Please note: for more information on netiquette, refer to the section on the Information security website.

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