Q. |
What is a list server? |
A. |
List servers date to the very beginnings of the Internet, when electronic mail was the
only method of communicating with users of different networks. Since they were
developed when there was no World Wide Web, Usenet (Newsgroups), or RSS feeds, list
all interaction can be entirely by email.
As such, a list server is a distribution list that lives on a mail server and is
used by authorized personnel to broadcast information simultaneously to a large
audience.
- Unlike other types of distribution lists, most, if not all, interaction with a
list server, is done via email.
- Examples of activities that can typically be accomplished include subscribing
to the list, cancelling a subscription, suspending a subscription (as for a
vacation), and getting summaries of, or individual messages from an associated
message archive.
- List servers strike a balance between sending individual messages to each member
of the list and sending one message to the entire list. They do this by sending
as many messages to groups of, say, 25 each, as are necessary to cover the entire
list. For example, if a list has 5,000 subscribers, the server might send 200 messages,
each addressed to 25 of the subscribers, rather than 5,000 individual messages.
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Q. |
How does a list server differ from a newsgroup? |
A. |
- Although modern list servers have Web interfaces, list servers can, by
definition, function entirely within the context of an email system.
- Newsgroups, on the other hand, can be more interactive, because they use
NNTP, or Network News Transfer Protocol, which can distribute messages
"live" to a large audience.
- Because NNTP offers more immediate distribution of messages to an audience, it
requires significantly more bandwidth than does email, which uses SMTP,
or Simple Mail Tranfer Protocol, to relay the mail from one server to the next
until it reaches its destination. It is this characteristic that causes email
to occasionally be slow about delivering the mail.
|
Q. |
How does a list server differ from other types of distribution lists that are part
of every modern mail server program?
|
A. |
All modern mail server programs, such as Microsoft® Exchange and Lotus
Notes™ include a distribution list feature.
- Unlike a "normal" distribution list, a list server can be used by
by anyone who has an Internet email address. Other types of distribution lists
are restricted to people who have a mail box on the server that hosts the list.
- If the list is configured to allow it, you may subscribe to the list, or cancel
your subscription, automatically. Although the details vary, they usually
involve either sending a specially formatted plain text message to a special
address on the server, or completing a Web form and responding to a special
"probe" message.
- Regular distribution lists, such as those found on Microsoft Exchange servers,
cannot be updated except by an administrator. If the list owner wants the same
degree of automation found in list servers, some custom programming must be done.
- Desktop email programs also support a type of distribution list. However, such
lists provide no automation whatsoever, must be used with care to avoid exposing
your mailing list to every member of your list, and greatly increase the risk of
being flagged as "spam" because of the large number of addresses in
each message.
|
Q. |
What advantages does a list server have over a mail merge list,
such as the address book that is part of your email program? |
A. |
Desktop word processing programs can generate individually addressed messages to
each member of a potentially large and dynamic list, using their mail merge
feature. However, for all but the smallest list, there are potentially
huge problems with this approach.
- Unless you connect the data base to a Web application, or subscribe to
a service such as Plaxo™, outsiders cannot update their own information.
- Because each message is individually addressed, there is one message for each
address on the list. This puts a huge load on your outgoing mail server.
- If your outgling mail server belongs to your ISP (Internet Service Provider),
the large volume of outgling mail may put you at risk of being unfairly tagged
as a source of SPAM, or UCE (Unsolicited Commercial Email). In extreme cases,
this could lead to termination of your account.
- You, or someone in your organization, must maintain the list, using a
spreadsheet, a specially formatted word processing document, or a data base
program.
|
Q. |
What is a "probe" message? |
A. |
A "probe" message is a special message, usually sent by periodically
by the list owner, to verify that the registered addresses of the list members
are still valid. Most probe messages have a dual purpose.
- The message reminds current subscribers of important administrative aspects
of the list, such as instructions for subscribing through a different email
address, leaving the list, and its terms of use.
- Messages sent to addresses that are no longer valid are teturned to the list
owner, who may use them to purge the list of dead addresses. Depending on the
number of subscribers, this may be a manual or automated process.
|
Q. |
Who can post, or send messages, to the list? |
A. |
The answer depends on the type of list. Most servers can host all types.
- Moderated List - Only designated people, called "moderators,"
naturally, can post. Others who want items posted to the list must submit the
item to the moderator. You usually do this by sending your message to a special
address, which may, itself, be another, private, list, to which all the moderators
belong.
- Unmoderated List - Any subscriber may post to the list. There may be
rules about acceptable and unacceptable content. The penalty for posting a
message that is deemed inappropriate, in the judgement of the list owners, is
usually a stern warning for a first offense, and expulsion from the list for a
second offense.
- Announcement List - Only the list owner may post.
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