Can I adjust the fields displayed on the New Comment page?
You are using the New Comment page included with Email to Case Premium, and would like to adjust which fields are displayed.
The New Comment page contains two specific sections where Case fields are displayed, Summary and Edit Fields.
In Salesforce Classic, administrators can use the "New Comment Case Fields" fieldset to control which fields display in the Edit Fields section. For the Summary section, the Subject and Description fields show by default and administrators can NOT add/remove fields.
When using the Timeline Lightning Component in Lightning to access the New Comment page, administrators can use the "New Comment Case Fields" and the "New Comment Case Summary Fields" fieldsets to control which fields display in the Edit Fields and Summary sections respectively.
Please note that fields included in the Summary section are always Read-Only.