Iphone SMS notification has been muted.

The other party's mobile phone is in mute mode, and the other party has turned off the SMS alert tone.

1, the other party's mobile phone is in mute mode: when the SMS on iPhone shows "The other party has muted the notification", even if you send the SMS to the other party, the other party's mobile phone will not make any sound or vibration, so the other party cannot receive the message in time.

2. The other party has turned off the SMS prompt tone: because the other party doesn't want to be disturbed, or in an environment that needs quiet, such as meeting, studying, sleeping, etc. In this case, the other party's mobile phone can still receive short messages, but it won't make any sound or vibration.