GNU Mailman is a mailing list management software. Mailman project was started long time ago before the Millennium. Since its birth it has become the most intelligent tool for handling mailing lists ever. Huge number of companies with Fortune 500 members among them have been using Mailman for years. The new version Mailman 3 brings to us even better user experience and communication power.
Sympa - Sympa is an open source (GNU GPL) mailing list management (MLM) software.
Gaggle Mail - Gaggle Mail is a simple and easy to use email list manager.
Listmonk - Send e-mail campaigns from a powerful dashboard. High performance and features packed into one app.
Google Groups - Google Groups allows you to create and participate in online forums and email-based groups with a rich experience for community conversations.
Mailman - Mailman is free software for managing electronic mail discussion and e-newsletter lists.
LISTSERV - LISTSERV is a communications server software that professionally manages the message traffic for email, blogs, and more.