Make new functionality optional

src/pretix/api/serializers/organizer.py

@@ -75,6 +75,14 @@ class CustomerSerializer(I18nAwareModelSerializer):
                   'locale', 'last_modified', 'notes')
 
 
+class CustomerCreateSerializer(CustomerSerializer):
+    send_email = serializers.BooleanField(default=False, required=False, allow_null=True)
+
+    class Meta:
+        model = Customer
+        fields = CustomerSerializer.Meta.fields + ('send_email',)
+
+
 class MembershipTypeSerializer(I18nAwareModelSerializer):
 
     class Meta: