Can the SMS of the arbitration notice be sent to the defendant's family?

You can't. The notice of arbitration is sent directly to the parties or their agents who need to be notified, rather than to the family members of the defendant. Because the defendant's family is not directly related, the main purpose of the arbitration notice is to inform the parties about the arbitration matters and inform them to participate in the arbitration proceedings. Therefore, in order to ensure the effectiveness and timeliness of the notice, the arbitration notice should be directly mailed or served to the parties or their agents, not to their families. If the party concerned or his agent cannot be notified directly, the notifying party may take other appropriate legal procedures to serve the notice, but it needs to ensure that the notice is legal and effective.