Using New Outlook on Windows for personal email, calendar, and contact management
This has nothing to do with "Sales Copilot". This is about M365 Copilot.
I see that you just went & plugged in the question to Copilot yourself and pasted it in - even though the answer is completely wrong.
Hope that you're not making a habit of copy/pasting Ai generated answers without having any knowledge about the subject matter being asked in a particular question.
I previously opened a case to Microsoft (in January '24) for this & there is no option to disable the "Summary by Copilot" in Outlook without disabling M365 Copilot altogether. Microsoft suggestion is to, after using Copilot, select the "thumbs down" button and provide feedback so that they eventually incorporate the option to disable this from Outlook.