Joining the Crowd with Mailing Lists
Once you become familiar with the idea of sending a message to an individual through the Internet, it isn’t much of a leap to imagine that with a slight change or two, you could actually send the same message to a group of dozens, hundreds, or even thousands of users, all without incurring any charge.
Imagine that you’re sending a letter to a post office with a really fast copying machine and a big list of addresses. If you send a letter to, for example, all homeowners in your neighborhood, you’d need to send only one copy of the letter, and the post office would duplicate it and send copies to every registered homeowner - for free.
That’s exactly how mailing lists work on the Internet. A central computer somewhere on the network maintains a list, and then anyone on the list can send e-mail easily to everyone else on that discussion list by addressing it to the so-called list server machine.
If you’ve ever thought about what it must be like to maintain current names and addresses for a magazine like TV Guide, you wouldn’t be surprised to find that it’s quite a lot of work. Electronic mailing lists on the Internet are quite involved also, but the good news is that computers can make the process considerably easier.
The most common software package used to maintain lists on central computers is called Listserv (without the trailing e for mundane historical reasons). To sign up for a list that uses the Listserv software, send an e-mail message directly to the Listserv program, requesting that you be added (or removed) from the specified list.
With 20,000,000 users, there are also a lot of mailing lists, enough that a list of them with one-line descriptions come to almost 400,000 bytes. At last count, there are almost 8,000 mailing lists, ranging from medieval literature and issues surrounding consulting to a list that offers tips on working with Microsoft Word on the Macintosh and a popular list that discusses the commercialization of the Internet itself.