The mobile phone is temporarily unable to connect to send SMS.

You should be talking about Unicom's secretarial business. Unicom secretary has a function to remind you of missed calls. When you are not in the service area, the Unicom secretary will record the missed calls for you. When your mobile phone is turned on or returned to the service area, the system will inform you of the missed information through SMS, so that you won't miss important calls. Yuan, secretary of Henan Unicom, has a monthly fee. You can open the secretary of Henan Unicom in the following ways: 1. Edit the short message "KTLTMS" locally and send it to10010; 2. Manually open or call the 100 10 customer service hotline through the business hall; 3. Log in to the online business hall for self-service. Tips: 4G users don't support SMS and Internet Hall for the time being.