Which of the following can be used to send emails to a large group at one time?

Groupware is collaboration software that can distribute one email out to a large set of users together.

LISTSERV is dedicated mailing-list software that also broadcasts to many subscribers at once.

Group by itself is a vague label, not a specific tool for mass mailing.

A mail server routes and stores mail generally but is not by itself the group-broadcast tool named here.

Groupware suites bundle email, calendars and shared documents for teams.

Examples of groupware include Lotus Notes and Microsoft Exchange based systems.