You can see whether the messages you send are successfully delivered to all the people you send them to.
To see the message summary for an announcement you've sent, click the "Delivered to" option in the header of the announcement.
The message summary will show you who the announcement has been delivered to and whether there were any delivery errors. You can click on people's names to learn more about what caused an error. In the message summary, you'll also see exactly who has read the announcement and any reactions they may have left.
To see whether a message in a conversation has been delivered, check the status below the message. If the message has been successfully delivered to everyone in the conversation, you'll see a green checkmark. If there was a delivery error, you'll see a yellow exclamation point.