Want to Create Virtual Column Display a numeric summary of the rows in each group

[Public_Works]

Want to create a Virtual Column that will count the value of a column

Example Column [Email Address] Lets say i have 3 hot@hot.com, and 5 cool@cool.com

I want the virtual column to count the email in this column and tell me the number count.

I have tried Count(list([Email Address]) and i only list the 1 value