Sending Bulk Email(s) to Customer:
You can send bulk email to your customer for this Navigate: 'Click on (Compose email icon) ---> Click on Customers ---> select Department ---> select Workcategory'.
Email will be received to all those customer to whom respected workcategory belongs to.
eg. In Department Income Tax, Workcategory - Company Return ITR 6 there are 10 customers under the selected workcategory so, after selecting particular department and workcategory you can send email to those 10 customers.