A mailing list is a listserv or a group of email addresses that receive the same e-mail messages.  In order to be part of a mailing list you need to subscribe to the list.  Mailing lists can be valuable and educational as they detail a variety of excellent educational discussion forums that you can participate in through electronic mail.

However, my advice is to stay away from mailing lists.  In my experience, whenever I have subscribed to a mailing list I have been flooded with uninteresting and unnecessary email messages from businesses trying to sell products, researchers pushing questionnaires and surveys, and other companies attempting to build their clientele online.  It really becomes a nuisance when you have over one hundred new messages in your email inbox and only ten of them are personally addressed to you.

Be careful when subscribing to mailing lists.  Understand that you will probably receive more mail than just the one newsletter or article you were expecting.