Using Classic Outlook on Windows for personal email, calendar, and contact management
Hello Julian,
Thank you for posting to Microsoft Community.
I understand that you have an issue where Outlook is showing "from" field when replying to an email addressed or cc'd to you.
Can you, kindly check if you have the option to "show fields" when replying to a message in the Outlook ribbon. If you do have only one email account in your outlook 365, you can deactivate the "From" field which I assume is active. Please see screenshot below.
If you do not see the "Show fields" option, please share with me a screenshot of your Outlook ribbon when replying to an email.
Looking forward to your response.
Best Regards,
Ashraf