In what way does the other party check the short messages sent by the telecom mailbox?

Telecom's 189 mailbox can only send emails in groups, but can't send short messages.

189 mailbox is a new generation mailbox service provided by China Telecom for telecom, mobile and Unicom mobile phone users and telecom broadband and fixed-line users. It has the basic mail service function of the conventional Internet, and makes full use of the mobile advantages of mobile phones, so that users can surf the Internet through SMS, MMS, WAP and mobile phone clients to handle mail anytime and anywhere.