Hi kmcgee,
1) Are you sure the items entered from cusotmer portal are getting assigned the "defect found" workflow step?
2) You can either do a global or project notification to the [assigned to] user.
For Global Notification go to Tools > Manage > Email Notifications > click on Global Notifications > Click on Add > Under OnTime Users scoll down to [assigned to] user > Now select the notification types you want this user to be notified.
or
For Project Level > go to the Project > click on project wiki tab (assuming you are on Ontime V8) > Click on Project Notification List Tab > Click on Add > Under OnTime Users scoll down to [assigned to] user > Now select the notification types you want this user to be notified.
Thanks,
Arash