There are no contacts or ordinary mails in the address book. What happened?

When the SMS of Apple's mobile phone is displayed, there may be two kinds of SMS: "contact and ordinary SMS" and "not in the address book".

This happens because the switch for filtering unknown senders under messages is turned on.

When the filter unknown sender switch is turned on, iMessage notifications from non-contacts will be turned off and messages will be classified separately.

If you don't want to see the display mode of "Not in Address Book", just turn off the switch behind "Filter Unknown Senders".

The operation steps are as follows:

Point setting;

Integral information;

Find and filter the unknown sender, just close the beginning at the back.