The topic has 3 posts, of which this is called post 2 or part 2.

1. Part 1: This post covers sending email with a link to the report only if the total number of records are NOT zero i.e. not a blank report. I highly recommend going through it before moving forward here
2. Part 2: This post  will cover how to use some logic to set conditions/break points beyond the report aggregate values# 
3. Part 3: The third post (link to come here) will cover sending the actual data in the email template rather than sending the link to the report##

Without any further adieu, lets get to the use case:

Use-case: Send email with report link only if a particular user has more than 15 open cases at the end of the day

Let say the report is:

Although under the subscribe report we can set a condition, but that condition is limited to report grand total only. e.g. the following (see screenshot below) will only take into account total cases open and NOT per user.

So the SOLUTION lies in transforming our report using report custom summary formula (CSF) to set the report grand total to a value that will trigger the chatter post. 

Step1: We create the CSF:

Step2: Subscribe to the report and use the Fire alert field:

Step3: Refer to part 1 of this series of blog to send the email only when a chatter post is posted. (go to part-1)