In order to uninstall an AppExchange app, you must remove every association its components have in your Org's configuration.

Email to Case Premium comes packaged with two email services, respectively named "Email to Case Premium" and "Black Hole". Both email services must be deleted to successfully uninstall.



Please refer to the instructions below outlining on deleting these email services.
 

Step 1: Locating your Email Service

• From Lightning Experience, navigate to Setup | Platform Tools | Custom Code | Email Services.
• From Salesforce Classic, navigate to Setup | Build | Develop | Email Services.

• Once on the page, there will be at least two Email Services (Email to Case Premium & Black Hole).

Step 2: Deleting the Routing Address(es) - Part 1

• Clicking the Name of the Email Service (per the screenshot above) will open up a new page with additional specifics.
  • Here we have opened the "Email to Case Premium" email service.

• From here, click the "View" button.
  • You will need to click the "View" button next to all routing addresses if multiple exist.
  • Note: The email service cannot yet be deleted as routing addresses still exist. We'll address this in the following step.

Step 3: Deleting the Routing Address(es) - Part 2

• After clicking the "View" button, you will be brought to a page that resembles the following.

• Click "Delete" to remove the routing address.

Step 4: Deleting the Email Service

• After deleting the routing address(es), you'll be brought back to the detail page of the email service.

• Click the "Delete" button to proceed with completing the email service deletion process.

Repeat Steps 1-4 for the "Black Hole" email service.