PM notifications are now handled by Dazah. This means the notifications themselves will be originating from Dazah instead of from DaniWeb. The benefit of this is that you can go into your Dazah settings and configure whether you would like to receive instant notifications, a daily digest, or suppress notifications.
Dazah has more robust notification handling and so, even with the Instant notifications setting enabled, you will no longer receive a notification for every message received while you're engaged in a long back-and-forth chat.
Additionally, you can disable message notifications in Dazah while still receiving the DaniWeb monthly newsletter and other DaniWeb-related community mail.