In order to send a mass email to all your guests please go under the "Guests” tab on your back office.

Then select all your guests using the “Sel” column

Once all your guests have been selected, click on the email button. 

Select the email you wish to send out from the drop down-menu.

With the "Preview" button you can preview all the emails that are going to be sent out to your guests.

With the "Send" button you will send out your email to the selected guests, this can take a few minutes if you have a lot of participants.