Last updated: 2018-11-30

Source: https://support.freshdesk.com/support/solutions/articles/237346-is-there-a-way-to-send-a-notification-to-all-customer-at-once-

We do not have an option to bulk email all your customers at once. You can make use of Mailchimp to send out these emails.

However, if you are wanting to notify customers who have raised tickets then you can make use of the Bulk Actions present in the Ticket list view and send out the emails to 30 tickets at a time.