For the scheduling of reports, it makes sense to send an alternate email when a report returns zero results as a piece of OOTB functionality. 

For example:

A manager receives an email once a week of delayed cases. 

At the end of the week he receives an email all the same, they have to open the attachment for it to display

"0 Results"

Instead, the email would have no attachment and could simply say "ReportName has  returned no results" in the body of the email. Removing the need for generating the file and notifying the user earlier about the result of the email. 

That or, you could just create the generation of a correspondence rule where a user could populate their "no results returned" email body.

Any sort of configurability on these scheduled reports would be very helpful, whether it be preventing an email being sent or being able to modify the body of the email. 

Thanks :)