Certificates can be mailed upon the completion of the Group , Course , Quiz and Lesson.
Goto LearnDash Settings Multiple certificates for LearnDash
Under the respective tabs of course / Group / Quiz/lesson, you will find the settings for enabling email notification
Note: These settings are global and will apply to all Groups/ Quiz / Courses and lessons

1. Enable certificates upon course completion: Enable this setting for automatic emailing certificates upon completion of respective milestone
2. Subject: The email of the subject goes here
3. Cc: This is a list of comma-separated email addresses for marking the certificate mails in Cc
4. Body: Here you can draft your personalized email body for better personalization make use of placeholders like Full Name, Course Name, Quiz Name, etc
5. Disable saving to server: By default, the certificates are saved in uploads folder under the MCDLD-multiple certificates folder in this directory you will find four sub directory containing the. Course: quiz/group/lesson certificates.

If this setting is disabled the certificates will not be stored in these folder