Rely on CSS for font formatting
Supported on: At least Windows Server 2008 R2 or Windows 7
Registry
HKCU
software\policies\microsoft\office\16.0\common\mailsettings Value name: usecssinhtml
Enabled: usecssinhtml = 1
Disabled: usecssinhtml = 0
Description
This policy setting allows you to configure the "Use Cascading Style Sheets (CSS) for appearance of messages" option found under Microsoft Outlook's File tab | Outlook Options | Mail | Message format. If you enable this policy setting, the option is checked. If you disable or do not configure this policy setting, the option is not checked.