Outlook can display email messages and other items in three formats: plain text, Rich Text Format (RTF), and HTML. By default, Outlook displays email messages in whatever format they were received.
Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Outlook Options >> Preferences >> E-mail Options "Read e-mail as plain text" is set to "Enabled".
Procedure: Use the Windows Registry Editor to navigate to the following key:
Criteria: If the value ReadAsPlain is REG_DWORD = 1, this is not a finding.
Fix Text (F-55277r811182_fix)
Set the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Outlook Options >> Preferences >> E-mail Options "Read e-mail as plain text" to "Enabled".