A mailing list is a collection of email addresses which receive the same email simultaneously. When you send a message to the mailing list address, it will be re-sent to all the addresses on that mailing list automatically, but none of the receivers will know who the rest of the recipients are. Generally, users have to subscribe to a list, but occasionally email addresses are included manually without the awareness of their owners. Depending on the given list management software, you may also be able to add new mailing list subscribers, so users cannot sign up for a mailing list unless you okay their signup request. The mailing list option is exceptionally handy in case you want to send newsletters on a regular basis or some other kind of periodic announcements to clients, since you will need to send one single e-mail message and all of the mailing list subscribers will receive it immediately. As a consequence, you will not need to write a lot of mailboxes manually.