Learn in the textbookHow Email Works and Specifying Recipients
DefinitionA mailing list (メーリングリスト) is a mechanism that delivers mail sent to one shared address to everyone registered.
ExplanationThe roster is kept on the mailing list's side, so a sender can reach everyone without knowing a single individual address. Adding or removing a member takes nothing more than editing the roster.
AnalogyLike telling an organizer once and having them pass the same notice to everyone on the roster.
Memory hookThe "list" in the name is the roster, so the name itself states what the mechanism is built on.