There is no built-in feature to send bulk emails from Firebase. The only built-in email sending capacity is around signing in with Firebase Authentication, and the contents of those emails is tightly controlled by Firebase to prevent it being used for sending spam.
If you want to send your own emails from Firebase you'll have to build it on top of Firebase, typically using Cloud Functions as sending email reliably is best done from a trusted environment.
Two examples of sending emails from Firebase:
- Using the trigger email extension, which sends an email when data is written to the Firestore database.
- Using the email confirmation sample for Cloud Functions, which works similarly as the extension.
Both of these require you to provide your own SMTP server details, which means you are in control of abuse prevention.