You can use Conversations to send a message to your entire class.
Messaging the entire class is a course permission. If you cannot send a message to the entire class, your institution has restricted this feature. Additionally, if your class contains more than 100 users, your message will automatically be sent as individual messages to each user.
- Students will only appear in your course once they have accepted the invitation to join the course. If you are trying to message students before your course has started, make sure you publish your course so invitations can be sent to your students.
- Once your course has concluded, you cannot send a message to your entire class.
In Global Navigation, click the Inbox link.
Click the Compose icon.
Select the course you wish to message from the course drop-down menu.
Open Address Book
To send a message to the entire class, click the address book.
Click the name of the course.
Add a subject line  and type your message in the message field .
If you do not want students to see all recipients and replies in the message, click the Send an individual message to each recipient checkbox .
Click the Send button .
Note: If your class contains more than 100 users, the Send an individual message checkbox will be selected automatically, and your message will be sent as individual messages to each user.
Your message will appear at the top of your Sent folder until someone replies.