The concrete5 mailing list package allows you to send emails & newsletters to any group, and allows your users to easily subscribe and unsubscribe. And unlike other mailing list systems, the Mailing List package integrates well with your concrete5 site, doesn't require that you pay a recurring monthly fee.
This system consists of three main parts:
Need help? Check out the Troubleshooting Guide:
Note: Sending large volumes of bulk mail can create both technical and legal challenges. If you're using this to send out lots of messages, you should make sure your hosting company allows it, and you should make sure the list of emails complies with your local spam control laws. Also, if for some reason emails get flagged as spam or are not recieved, chances are it's going to be related to your concrete5 core & server configurations. I'll help you troubleshoot any issues you have up to the point where the emails are sent and logged in the reports page. If you still have any issues beyond that try enabling SMTP emails via the dashboard, setting up a SPF DNS record, and/or making sure the from email address is from the same domain as your mail server. However, for most installations these additional steps are unnecessary.
More information and troubleshooting assistance is available here: http://inneroptics.net/concrete5/mailing-list/troubleshooting/