It's something about Electronic mailing list

A mailing list (Email list Management) 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 is referred to as "the mailing list", or simply "the list".

At least two types of mailing lists can be defined: an announcement list is closer to the original sense, where a "mailing list" of people was used as a recipient for newsletters, periodicals or advertising. Traditionally this was done through the postal system, but with the rise of email, the electronic mailing list became popular. The second type allows members to post their own items which are broadcast to all of the other mailing list members. This second category is usually known as a discussion list.

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