Email notifications are only received if a course is due for renewal and if email notifications are enabled. If an email notification hasn't been received check the below to see if the course is due and also if notifications are enabled.
Check if the course is due for renewal
Run a compliance report to see when courses are next due to be completed.
Check if email notifications are enabled
Check notification preferences in the Admin Tool
If notifications are enabled but emails are still not being sent, raise a support case so the team can investigate further.