The short message is stored in the server magnetic stripe machine.

1, SMS can be stored in the magnetic stripe function of the server for three months to six months. If the transmission is successful. When the receiver can accept the short message, HLR will inform SMC, which will send the short message and delete it automatically after success. How long to save depends on the operator's settings, generally 24 hours.

2. If the transmission is unsuccessful. SMC will only store short messages when the receiver is full, unreachable and turned off. When the receiver can accept the short message, HLR will inform SMC and SMC will send the short message. This situation lasts for 7 days at most and 7 short messages at most.