How do you send a message to all of your guests? Broadcasting a message will send your message to all of your guests. Each message is sent to your guests privately. You can find the Broadcast option on the first page of the Messages tab on your invitation.
From there, you can select "All Guests" and then send your desired message to your guests.
You can also send a Broadcast message after selecting "New Message" and then selecting at least two guests, and then selecting "Start Broadcast Message."