The Email Sender tool allows user to send an email message to site participants by role, section, or group, and also provides a field for specifying non-site participant email addresses.

The Email Sender tool works using the sender's email address. Details regarding which address is used are in the article, What is the email address for my Sakai account?

Note: The Email Sender tool can work in conjunction with the Email Archive tool to post email messages to the course archive.