CCS per user

In most cases I use the 7CCS(high) per user for traffic in a voice network.

In the new work environment that many communications among employees (station to station TRF) are done via Email rather than a phone, is there a new model that reflects this change in Traffic assumptions?

Can I use the 5CCS as my model for high traffic user , knowing that part of their communication has been done through Email ?

Thanks for your input, It will help if you can refer me to a white paper or any article addressing new Traffic measurment standards. Thank you much.