i think email case capture is designed to work with customers only, so for it to tie to an employee record specifically, you'd need scripting/maybe workflow involved to link the employee. if you just need to know the employee's name but not specifically tie it to their employee record, you could also potentially create customer records for each employee (again maybe using a workflow/script to automate that creation) with their email address, so it would automatically link it ot that employee "customer", but then you risk clogging up the customer list.