Newsletters are an extremely valuable marketing tool used by any online community owner to maintain contact with their users - their customers. You can use the built-in Newsletter to send out emails to some specific users to notify about your site or your plan. It is a built-in feature in your Admin Control Panel.
phpFox provides a great tool for working with newsletters. Each newsletter can be customized to be sent out the whole members, or it can be flexible targeted just a group of specific users. The newsletter's content is no more boring with plain text since you can compose a message with the powerful rich-text (What You See Is What You Get) editor.