A mailing list is a collection of email addresses that receive one and the same email simultaneously. When you send an e-mail message to the mailing list address, it will be forwarded to all the addresses on that mailing list automatically, but none of the receivers will know who the other recipients are. In the general case, users have to subscribe to a mailing list, but occasionally email addresses are added manually without their owners’ permission. Based on the particular mailing list administration software, you may also be able to include new mailing list subscribers, so users cannot join your mailing list unless you authorize their signup request. The mailing list option is very valuable in case you want to send regular newsletters or some other type of regular publications to customers, as you will need to send just a single e-mail and all of the subscribers will get it instantaneously. This way, you won’t need to enter many email addresses manually.