How to turn on dark mode in Microsoft Outlook to change your display and reduce eye strain

To turn on dark mode in Outlook, click the File tab, choose Office Account, and set the Office Theme to black.

How to change the default font in Microsoft Outlook from 'Calibri' to one you prefer more

To change the font in Outlook, head to the "Signatures and Stationery" menu, where you can pick from a number of fonts.