Source : WordNet®

mailing list
     n : a list of names and addresses to which advertising material
         is mailed

Source : Free On-Line Dictionary of Computing

mailing list
     
         (Often shortened in context to "list") An
        {electronic mail address} that is an alias (or {macro}, though
        that word is never used in this connection) which is expanded
        by a {mail exploder} to yield many other e-mail addresses.
        Some mailing lists are simple "reflectors", redirecting mail
        sent to them to the list of recipients.  Others are filtered
        by humans or programs of varying degrees of sophistication;
        lists filtered by humans are said to be "moderated".
     
        The term is sometimes used, by extension, for the people who
        receive e-mail sent to such an address.
     
        Mailing lists are one of the primary forms of hacker
        interaction, along with {Usenet}.  They predate {Usenet},
        having originated with the first {UUCP} and {ARPANET}
        connections.  They are often used for private
        information-sharing on topics that would be too specialised
        for or inappropriate to public {Usenet} groups.  Though some
        of these maintain almost purely technical content (such as the
        {Internet Engineering Task Force} mailing list), others (like
        the "sf-lovers" list maintained for many years by Saul Jaffe)
        are recreational, and many are purely social.  Perhaps the
        most infamous of the social lists was the eccentric bandykin
        distribution; its latter-day progeny, {lectroid}s and
        {tanstaafl}, still include a number of the oddest and most
        interesting people in hackerdom.
     
        Mailing lists are easy to create and (unlike {Usenet}) don't
        tie up a significant amount of machine resources (until they
        get very large, at which point they can become interesting
        torture tests for mail software).  Thus, they are often
        created temporarily by working groups, the members of which
        can then collaborate on a project without ever needing to meet
        face-to-face.
     
        There are several programs to automate mailing list
        maintenance, e.g. {Listserv}, {Listproc}, {Majordomo}.
     
        Requests to subscribe to, or leave, a mailing list should
        ALWAYS be sent to the list's "-request" address (e.g.
        [email protected] for the IETF mailing list).
        This prevents them being sent to all recipients of the list
        and ensures that they reach the maintainer of the list, who
        may not actually read the list.
     
        [{Jargon File}]
     
        (2001-04-27)