Email discussion groups are emailed discussions, or threads, that are forwarded to a group of people. Usually, they cover a specific topic of interest, and countless such groups exist. Some lists are moderated by a listowner willing to take responsibility and remove offensive posts; other discussion groups are not moderated. This form of communication was one of the first methods of group conversation online, predating forums by several years.
Joining a discussion group is usually done by simple request. You ask to join by submitting requested information and your email is added to the list for that group. This can result in an immediate flood of emails, but most listserves offer a digest option, where many messages are combined into a single email. When an email response is sent, it is forwarded to the entire group, often resulting in discussions branching off in different directions.
So many discussion groups exist that finding one is just a matter of searching for your interest or browsing lists to find one that is appealing. Many websites, like Yahoo Groups, MSN Groups, Coolist.com, and Freelists.org provide free group hosting, and some offer customizable pages and administrative features for anyone who wants to start a new list.
General Discussion Group "Netiquette"
As with any group situation, there will be specific rules outlined by the listowner, but here are some general guidelines that can be expected from any discussion group:
Keep it short - these discussions can get very long, so keep your posts as succinct as possible. Avoid long signature lines or tags that can be misinterpreted as part of the discussion.
Relevant subject lines - The subject line should be an indication about the subject of the email. Also, spamlike subject lines should be avoided. Spamlike subject may seem funny at the time, but if enough people mistake it for spam, the list is likely to be blacklisted and undeliverable.
Proofread! - While typos can be overlooked, consistent sending of poorly constructed emails lacking in grammar and spelling can result in ridicule or even removal from the list. Ideas expressed incoherently will not be taken seriously.
Don't post angry - Any discussion can become very emotional. Before sending an email rant that could destroy your credibility within the group, wait until you are calm and read it again before deciding to send.
No abuse - Everyone is expected to behave in a mature manner. Language should remain as polite as possible. Insulting comments may be tolerated, but attacks and name-calling are unlikely to be accepted.
No selling - Unless the focus of the discussion group is marketing, don't use your list as a marketing tool.
Here are some collections of email discussion groups:
edwebproject.org Education-focused discussion groups.
CataList The official catalog of Listserv lists.
Herp-Related Email Lists and Discussion Groups
Cancer - related groups Anthropology groups
Votex-L Discussions on unconventional physics
Children's literature lists
Family discussion lists
Adventist Sabbath school lists
NASA Astrobiology Institute Astronomy Focus Group
WOMENTECH TALK Listerv
webliminal.com Usenet groups
FTP site information
Stone Conversations International discussion for people who work with stone
Whatever your interest, an email discussion group of like-minded people exists. Email lists are also ideal for family groups; even the least technically savvy person can be taught to send an email.