How can a stranger send a message by making an appointment in advance?

Make an appointment in advance and explain the situation and time. Adding a respectful name to each sender will make the message more human and intimate. There is a store name in the short message, so don't let customers see it and don't know what they are doing. This is not helpful for the promotion of the store. So when you send a text message, you must add the name of the store. But the signature must be short: when someone sends a message to a customer, add "limited liability company".