139 mailbox can't be sent out. There are sensitive messages.

Hello! In order to create a green grid communication environment, 139 mailbox has an automatic garbage monitoring and filtering system, which will judge the nature of self-written short messages according to the sending frequency and short message content of users before sending them. It is recommended not to send a large number of promotional short messages with the same content or containing phone numbers and addresses in a short time, and the sending frequency must be controlled. I hope I can help you!