Bulk email templates contains many edX-specific reference (and are thus unusable)

[regisb]

Bug description

Emails sent via the Bulk Email feature use a terrible template:

This template comes from the course_email_template.json fixture. This fixture is loaded in a data migration.

This issue occurs both in Tutor and the native installation.

How to reproduce

1. Sign in to the Django administration console for your base URL. For example, http://{your_URL}/admin.
2. In the Bulk_Email section, next to Bulk email flags, select Add.
3. Check the Enabled check box. Uncheck the "Require course email auth" check box.
4. At the bottom of the page, select Save.
5. The instructor tab of the demo course should now include an "Email" tab. Use it to send an email to yourself.

Tutor should come with a usable template out of the box.

[regisb]

This issue is now tracked upstream by the BTR working group: https://github.com/openedx/build-test-release-wg/issues/100

[regisb]

Closed by https://github.com/overhangio/tutor/pull/621