On my phone (iPhoneSE running iOS 12.x) I rarely ever receive any legitimate phone calls, but I get loads of spam.
I would like to silence all calls except for my one Emergency Contact, but without impacting any other notifications at all.
This means I can't use Do Not Disturb because it silences all notifications.
Is there any way to silence all phone rings except for one person, but without using DND mode or otherwise silencing notifications?