Discrepancy in number of Active users under Office365 Email app on HEC

[ArsathParves1]

Hi Mates,

We are evaluating HEC for one of our client basically we have integrated Office365 Email, SharePoint & One drive app with HEC. But now we have a mismatch under the list of active users. In the client tenant they have more than 1400+ active/ licensed users which is correctly reflecting under Onedrive and SharePoint apps but under Office365 Email it's shows only less than 730 active users ?

Have any came across similar issue or is there a SK for me to go through to better under this issue?

Thanks in Advance 

Regards,

Arsath