WP Mailster!

Mailman is integrated with the web, making it easy for users to manage their accounts and for list owners to administer their lists. Mailman supports built-in archiving, automatic bounce processing.

Dada Mail is a contemporary mailing list manager, enabling you to easily run a verified mailing list that your subscribers can trust - right on your own website! Make running your business and personal mailing lists easy, fun, and inexpensive.

An email address for your group. Discuss. Debate. Organise. All with email. This is the most simple way to make a regular mail discussion list or "Listserv." Very commonsense and easy. Free version or an inexpensive paid version.

DeliPress lets you create beautiful newsletters in just a few minutes with our easy-to-use drag and drop Email Builder, all this while staying inside WordPress.

WordPress mailing group is a plugin that allows you to run a free Listserv or email group just like Google Groups or Yahoo Groups right from your WordPress dashboard. Group members can use their favorite email clients to interact with the group, no need to login to dashboard. They can send plain/text or HTML emails with attachments. The plugin offers various email sending options and also allows to add an SMTP server for outgoing emails.