Very easy to use and quick to setup. I have used it personally.
Mailman 3 - Dedicated Mailman 3 installation. Unlimited lists/configuration. Free subdomain at mailman3.com. Dedicated support for list admins.
Mailman - Mailman is free software for managing electronic mail discussion and e-newsletter lists.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
Listmonk - Send e-mail campaigns from a powerful dashboard. High performance and features packed into one app.
GroupServer - Email lists, with an integrated web interface, and control.
Listeron - An email address for your group. Discuss. Debate. Organise. All with email.