A list of email addresses to which messages are sent. You can subscribe to a mailing lists typically by sending an email to the contact address with the following in the body of the message: the word subscribe, the name of the list, and your email address. E-mail is, and has always been, the greatest application of the Internet. There are number of e-mails sent daily than the number of phone calls. When one thinks of e-mail it is usually regarded as a person-to-person communication activity. Mailing lists, though, encourage a greater and more varied amount of e-mail activity, anything from two-way communication to full interactive discussions open to the public.

You can create your mailing list using control panel as cPanel or Plesk.
Generically speaking mailing lists can be classified in two ways: a ‘one-way’, and a ‘two-way’ mailing list. A one-way mailing list either accepts or sends information, the user only interacting with the list server; and a two-way list creates interaction.