Examples are pine, elm, Berkeley mail, Pegasus Mail, and Eudora. mail transport agent or MTA Software that transports mail messages. Examples are sendmail or smail. In nn, this is when the list of authors and subjects of articles in a newsgroup are displayed. You choose the articles you're interested in by typing their IDs. A newsgroup that has a moderator, i.e., someone who looks at each article before it gets posted and decides whether it is appropriate.
Examples are comp.viruses and bit.listserv.nettrain .
The Net The Internet. All the thousands of newsgroups and articles that are distributed through the Internet. This includes Usenet and Clarinet news. Examples are nn, tin, trn, pine, Netscape, Free Agent, and News Express. A discussion area in Net news.