Using the Canvas Inbox
The Canvas Inbox is a helpful tool to message your instructors and classmates directly within your courses. To send a message, select the Inbox icon 
from the global navigation bar on the left side of your Canvas page:
To compose a message, select the button with the pencil icon in the gray margin at the top of the Inbox:
The Compose a Message dialogue box will appear. Select a course from the Favorite Courses menu (Note: only ACTIVE courses will appear here.)
At the end of the "To" line, select the Address Book icon 
to select who you would like to send a message to.
You can add attachments by clicking the paperclip icon
in the bottom left corner of the dialogue box.
You can add attachments by clicking the paperclip icon
Once you have typed your message, click the blue Send button.