Instructors and students would at times stop receiving email notifications from Canvas. One possible reason is the instructor's or student's email was added to Canvas suppression list. Canvas would add email to the list if it detects an email bounce back even if the email is valid. What causes the bounce back is not clear.
The current work flow is faculty, instructors or students would contact our support team that they are not receiving Canvas email notifications. We would check the owner's account, specifically if there is an exclamation icon next to their email. If we see this icon, there is a high chance the email is added to the suppression list. We would then contact Canvas Support and requests their email removed from the list.
The main problem is when an email is added to the list, the owner will not be notified.
Below is an example of how this problem affects students and instructors:
Assume an instructor's email was added to the suppression list. A student has an urgent exam question, so they tried to message the instructor using Canvas Inbox. Instructor will still receive the message, but they will not receive any email notification on receiving the message. The only way the instructor will know the student had messaged them is if they regularly check their Canvas Inbox or the student contact them in other ways.
If Canvas have a feature to notify the owner of the email prior to their email being suppressed, we reduce some of the steps in our work flow and get their email removed from the list a lot sooner.