Out of the box, the ServiceNow Outlook plugin maps the body of the email to the comments field rather than the description field, here is how to change that.
1. Modify the Create Incident Widget. Find this line around 118 and change comments to description
g_form.setValue("comments", result.value.trim());It gave me a message that the widget is read-only but it let me modify it. If that doesn’t work for you, you can clone it and then put the new widget into the Outlook Home page (outlook_index).
2. Change the Outlook view on the incident table to include the description field.