[Reports] Add email bounce count to the Communication Channel API

[stelpstra]

Situation

Frequently email addresses used in Canvas bounce emails while admin are completely unaware this is happening.

Possible causes:

• people start using other email addresses and close the previous one
• people change email addresses because their name changed because of marriage
• people change jobs, the old address is terminated and a new one created
• the university disables the university student email account for inactive students
• new mail is rejected because the mailbox completely full
• etc.

Currently Canvas does not (yet) offer a way to proactively identify these problems, while teachers assume all their students receive notifications of e.g. announcements, assignments, etc. as configured in the notification settings.

Suggested solution

Let Canvas keep a record of every bounce email returned when sending notification emails to users and when using the Communication Channels API return the value "bouncing" (or a better word) in the "workflow_state" field of the related user.

Edit: Canvas already stores a bounce count per communication channel (see bounce_count https://portal.inshosteddata.com/docs#communication_channel_fact), this field should be added to the Communication Channels API.

[stelpstra]

Please also vote for https://community.canvaslms.com/ideas/8403-download-an-admin-report-of-all-bouncing-email-addresses 

[James]

It shouldn't be in the workflow_state because it's contained somewhere else as a bounce_count. So instead of adding a state that is only available through the API, they should expose the bounce_count as explained in the communication_channel_fact table of the Canvas Data.

If this is greater than 0, it's bouncing.

[stelpstra]

Thank you  @James ‌, I have changed the idea description.