LISTSERV is mailing list software that manages a database of mailing list subscribed members and automatically routes each mail to all members. LISTSERV includes email list management features that provide automated management of typical tasks. For example, a user can subscribe and unsubscribe to the list or send a single email to all members. LISTSERV also provides automated back-end administrative tasks. LISTSERV operates independently and can be installed as a mailing list server on most operating systems such as Windows, Linux, UNIX, FreeBSD and more.

Being one of the first and most popular list servers, the brand name LISTSERV became synonymous with mail servers in general (similar to how Kleenex is a brand name for tissue paper). Sometimes people use the term incorrectly because of this.