It is possible to send email to many persons simultaneously by simply writing the email mailing list address in the To: field. The message first goes to the server which forwards it to the recipients on the list.
Many email programs can be used for making personal email lists but normally mailing lists refer to those centrally maintained by separate servers. A parallel public news system has also been developed.
You can subscribe on unsubscribe to a mailing list by sending a respective request to the list server, either a server program or a physical person. The form of the server address varies according to the program used but it is almost always different from the actual mailing list address.
The address of the server normally follows the form firstname.lastname@example.org address. Mailman, Majordomo and Lsoft Listserv are popular list servers. The form of the Majordomo server address is mostly majordomo@server address, whereas that of the LISTSERV server is listserv@server address.
To join a list, the most commonly used command is SUBSCRIBE. If you want to leave a list, use the command UNSUBSCRIBE . The commands in different list server programs can vary considerably, but most of them will probably reply if you type HELP.
You should not send subscription or unsubscription requests to the actual list, nor any other messages which are not intended for all persons on the entire mailing list.