diff --git a/apps/settings/serializers/email.py b/apps/settings/serializers/email.py
index 42618b611..6604eba6a 100644
--- a/apps/settings/serializers/email.py
+++ b/apps/settings/serializers/email.py
@@ -10,8 +10,8 @@ __all__ = ['MailTestSerializer', 'EmailSettingSerializer', 'EmailContentSettingS
 
 
 class MailTestSerializer(serializers.Serializer):
-    EMAIL_FROM = serializers.CharField(required=False, allow_blank=True)
-    EMAIL_RECIPIENT = serializers.CharField(required=False, allow_blank=True)
+    EMAIL_FROM = serializers.CharField(required=False, allow_null=True, allow_blank=True)
+    EMAIL_RECIPIENT = serializers.CharField(required=False, allow_null=True, allow_blank=True)
 
 
 class EmailSettingSerializer(serializers.Serializer):