Email Discussion Lists
Email discussion lists, also known as listservs or discussion groups, allow people with common interests to easily share information and participate in discussions by using a dedicated email address. For example, BEETALK might be the name of discussion list for people interested in bees. Its address might be firstname.lastname@example.org. To send a message to everyone on the list, only a single message need be sent to the list address. The message is received by the list processor which then distributes it to all list members (hundreds of people in some cases). In turn, as a member of a list, you receive copies of messages sent to the list by others.
People whose email addresses are on the list are referred to as subscribers. A discussion list can range in size from just a few subscribers to several thousand. Similarly, the number of email messages exchanged among participants can range from a little as one per month (or even per year) to hundreds per day.
KU IT offers two list serving methods: KU Group Lists and Mailman. Visit the Distribution/Group Lists service page to determine which option best suits your needs.
How Lists Work
Every email discussion list has one or more owners who are responsible for the smooth functioning of the list.
List Email Addresses:
The list address is the common email address subscribers use for sending group messages and responding. Messages sent to the list's address are distributed to all list subscribers. At KU, all Mailman list addresses are in the format LISTNAME@lists.ku.edu. In the example above, email@example.com is the email address of the discussion list. Some discussion list names end in -L (e.g., beetalk-L@lists.ku.edu) to help people distinguish the email address as one belonging to a list and therefore one that could potentially distribute a message to hundreds of people. KU Groups Lists have an "@ku.edu" address, and the name often has a "-DL" to show that it is a list address (e.g., beetalk-DL@ku.edu).
Every discussion list has one or more owners. We encourage list owners to include their email addresses in a welcome message sent to all list subscribers at the time they join the list. Owners are responsible for keeping the list functioning smoothly, and sharing the owner's email address in the welcome message allows subscribers to report any problems, such as inappropriate behavior by list participants, strange list behavior, such as missing messages or duplicate messages, or problems with subscribing and unsubscribing.
Types of Lists
Lists can be set up to have many features. The features of the list depend in large part upon the purpose of the list and the time commitment the owner puts toward the list. Many list configuration features can be divided into two broad categories, those that determine the way people join (subscribe) and those that determine the options for posting (sending messages). Many of the features are not mutually exclusive. That is, a list may be both moderated and private, for example. List owners should refer to Mailman's list administration manual or our Knowledge Base for information on adjusting their list configuration settings to create the type of list desired.
List Types By Subscription Method
Note: In the following examples, it is possible for the list owner to override the list configuration settings and add subscribers even if the list subscription type does not allow it.
A list that allows anyone to join is known as an open—or public—list. On an open list, anyone who subscribes to a list is automatically added to the list. This has the advantage that it doesn't require any work for the list owner. The disadvantage is that the list owner loses control over who can participate the list's discussions and leaves the list open to potential spammers. We do not recommend open lists due to the high potential for spam.
A private list is one in which the owner controls who may subscribe. Subscribe requests are forwarded to the list owner for approval. Such lists are not open to the general public and usually have a very specific focus. Potential subscribers may be asked to provide information about themselves and their experience with the topic before being allowed to subscribe. Private lists cut down on the amount of spam distributed to everyone on the list.
A closed list does not accept any subscription requests. Attempts to subscribe to closed lists are returned to the sender with a message indicating that the list is not accepting subscribers. Lists that are created for a very specific purpose and that have a finite set of participants are often configured as closed lists. For example, a committee at the university may establish a list specifically to facilitate communication among its members.
List Types Based on Posting Method
Closed vs. Open List:
Most lists allow anyone to post to the list. Anyone who knows the email address of a list can (attempt to) send a message to the list. It is not always necessary to be subscribed to a list in order to send a message. Such lists are called open lists. If you post to a list without subscribing, your message should make clear that you are not a subscriber and all replies should be emailed to you privately (otherwise, since you are not a subscriber, you will not receive the replies). A closed list is one in which only those who are subscribed can submit messages to the list. A closed list reduces spam because potential spammers must first go to the trouble of joining a list.
Moderated vs. Unmoderated Lists:
A moderated list is one in which the moderator must approve all messages before they are distributed to the list. The moderator also has the option of editing a message before approving it. Approved messages are then forwarded on to the list. This helps ensure that the posts are germane to the list's purpose and reduces the chance that heated discussions may get personal or out of control. This can, of course, represent quite a burden for list owners and also results in a delay before submitted messages are received by other list members. Moderation is usually done only for lists where the subject matter is of a personal/private nature or is such that heated discussions are likely. Most lists are not moderated.
In this instance, messages are sent only by the owner to subscribers. There is no opportunity for subscribers to respond to posts or to post new messages of their own. Examples of lists of this type include quote-of-the-day services, announcements and newsletters. Messages are distributed to subscribers from a central source (usually the owner) rather than from the group of subscribers.