28-01-2020 09:28 AM
Sorry for the delayed reply, hope you are well.
Just to confirm are you looking to change this in an Outlook mail client? If so, I would recommend checking this article out, and if that is not helpful there is also a support link there for Microsoft.
You can also change your sender name in the settings of the email if you log in at portal.office365.com, but the "from" email address would still remain the same in that instance.
18-07-2020 11:23 AM
At the top of the page, select Settings. > View all Outlook settings.
In the Options pane, under Mail > Sync email.
Under Set default From address, choose an address from the drop-down list.