It is possible to generate alerts for each logspace to send an alert if the SSB does not receive any logs in the last 24 hours. You would need to setup Message Rate Alerting (MRA) feature in the product by doing the following:
Navigate to Log and select Logspaces
Then select the custom logspace name you want the alerting on
Click in the Enable Message rate alerting box
Then fill in the fields for Minimum and Maximum values and check the Master alert box.
For further instruction on how to setup message rate alerting feature please see the "Configuring message rate alerting" section in the Admin Guide. Here is a link to the section in our online documentation: SSB Admin guide