Right now, DPM will send only one alert per triggered threshold. For example, if you have an alert to trigger on replication delay > 60 seconds, you will get one notification when it reaches 60 seconds and never be notified again if it continues to rise. It needs to fall below the reset threshold in order to be triggered again.
It would be great if in addition to the option of silencing repeated alerts (which exists) to have the ability to get notified repeatedly if the threshold remains met and not reset.