Create a job queue with the following steps:
1. Check for available updates
2. Terminate queue if previous ‘Check for available updates’ finds 0 updates
3. Send email notification
Then set that job queue to run as a scheduled task. When it runs it will send you an email notification if/when there are 1 or more updates available. In the next version of BatchPatch there will be additional conditional options available for the job queue to enable this task to be created in a couple of different ways, but in the current version you would need to do it like stated above.
The multiple tasks scheduler does not allow recurrence. Your options are either create a separate recurring scheduled task for each row (you can create more than one row per host, if desired), or use the multiple tasks scheduler and manually create all of the desired datetimes to run the task.