An electronic mailing list is a list of email addresses that receive one and the same email message simultaneously. When you send an e-mail message to the mailing list address, it will be redirected to all the addresses on that list automatically, but none of the receivers will become aware of who the other recipients are. In the general case, people have to subscribe to a mailing list, but occasionally mailboxes are included manually without the awareness of their owners. Depending on the given list administration software, you may also be able to add new subscribers, so people cannot subscribe to your mailing list unless you authorize their request. The mailing list functionality is extremely valuable if you would like to send regular newsletters or some other type of periodic notifications to customers, since you’ll have to send out a single e-mail and all the subscribers will get it momentarily. As a consequence, you will not have to write a huge number of email addresses manually.