Hi
No, the extension only allow you to send mass mails to registrants of one event at a time, not all events.
The solution is using Events Booking together with a newsletter extension called ACYMailing. Basically, you can config Events Booking so that when registrants register for the event, they will be assigned to your certain mailing lists.
After that, you can use ACYMailing to send newsletter to these registrants to inform them about new events
Regards,
Tuan
