Use is as simple as composing a memo and sending it off to its destination with a few key strokes. It is however mandatory that you know the correct e-mail address of your intended recipient. Any member of a list can, with one message, address all of the members of the list. Listservs are maintained at a single location and to write to the entire list, all that is required is a single message to the listserv. In principle, any group of e-mailers who share a common interest can start a listserv on any subject imaginable.
Lists can be open to all or closed to all but welcome applicants.
In addition, there are features which allow compilation of daily message packages rather than or in addition to allowing the individual retransmission of submissions as soon as they arrive. Some list owners also maintain archives of submissions. Newsgroups are topic specific. One simply posts information or a question in the form of an e-mail message to a newsgroup or newsgroups which seem appropriate for your interests. Since posting and reading are independent actions, and there is no obligation to do either, it is never certain who may read your posting.