Mailing lists are the best way to discuss topics with people around the world. There's far less "noise" than found on the Usenet newsgroups, and discussions are usually intelligent and insightful. There are also more mailing lists than newsgroups; although no one has an accurate statistic, it's likely there are more than 250,000 different mailing lists currently active.
Here's how a mailing list works: once you subscribe, e-mail messages begin arriving from others in the group. If you want to join the discussion, send e-mail to the mailing list address. Copies of your comments will automatically be e-mailed to all other subscribers, usually within a second or two.
Joining a mailing list is easy, and almost always free. (If there is a charge for subscribing, you will be asked to pay in advance--but never send credit card information through e-mail.) To subscribe, you will send e-mail to an address such as one of these:
To: listserv@vm1.mcgill.ca
From: Jane_Doe@monitor.net
Subject:
subscribe AUSTEN-L
That's all. No thank-you's, no signatures -- remember, this message is being interpreted by a machine. And please notice that the "subject" line is blank. When you join, you will be automatically sent a message explaining how to unsubscribe and how to send e-mail to everyone in the group.
Several web sites offer a searchable index to help you find interesting mailing lists. This means you can type in one or more keywords and it will show you every mailing list concerning that subject. The best searchable index is Liszt, which also lets you subscribe to a mailing list on the spot. Meta-List allows users to search for over 234,000 public newsletters and discussion lists by keyword or category and in thirteen different languages.
A different type of index is available from Stephanie da Silva. Here you'll find a smaller alphabetical list and subject list. Unfortunately, it's not searchable like the others, but it's good for browsing. And the Clearinghouse is also a great way to find mailing lists, as well as other Internet resources available on a particular topic.
None of these resources have a complete directory of all mailing lists. There is a list dedicated just to bumblebees, for example, that doesn't appear in any index. You often learn about such lists by reading other mailing lists or web pages.