A mailing list is much like a newsgroup in that you subscribe to a list based on its topic. The primary difference is that instead of visiting the newsgroup and reading messages of your choice, a mailing list will automatically send every post to the group to your email address.
For a mailing list to work, someone has to handle its management and administration: mostly signing up new members and removing members who have asked to be removed.
In a few mailing lists, that administrative task is handled by a real person. However, most mailing lists are managed not by a person, but by a list server . Sometimes, the mailing lists managed by people are called manual mailing lists, to distinguish them from the lists automated by list servers.