To enable email case capture go to Setup>Company>Enable features under the CRM subtab to enable Email Case Capture
This enables you to capture cases through email. To capture email cases NetSuite has an inbound email address to send cases to NetSuite. Go to setup>Support>Support preferences>Inbound Email
You can try sending case details to this email. A case record will be created in Netsuite with your mentioned details. Lists>Support>Cases. The case will be assigned to the support rep according to the case rules or by default.