We have historically sent an email every term that lists the courses students are registered for along with the corresponding Bb course ID. Other information has varied over the years, but currently includes instructions for accessing Bb courses, how to change Bb password, a note about ordering textbooks, a note about add/drop and withdrawal periods, technical support contact, and unique library barcode along with instructions for accessing the library.
I send the email through a mail merge 3 days before the start date. We do not have an integration with our SIS, so everything is done through CSV files.
I am curious to know if other institutions send a similar message, what the content consists of, whether you think this is helpful to students/are they even opening it, etc.