Log in to 189 e-mail by mobile phone. Why can't I send a short message?

For example, when you send a text message with 189 mailbox, there is always a question to remind people to enter * *. Please check whether the contact format entered in the contact column of the receiving mobile phone is correct (SMS can be sent to the mobile phone users of China Telecom, China Unicom and China Mobile, and the mobile phones are separated by commas). For more service benefits, click on "official website" customer service 324 below to answer your questions.