Default message format must be set to use Plain Text.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-71269	DTOO314	SV-85893r1_rule		Medium

Description
This policy setting controls the default message format in Outlook. If you do not configure this policy setting, new e-mail messages in Outlook are formatted as HTML. If you enable this policy setting, you can set the default e-mail format in Outlook to HTML, Rich Text, or plain text. Users can choose a format other than the default when composing messages. If you disable this policy setting, Outlook uses HTML as the default e-mail format and users will not be able to change it. If you do not configure this policy setting, Outlook uses HTML as the default e-mail format, but users can choose a format other than the default when composing messages.

Description

This policy setting controls the default message format in Outlook. If you do not configure this policy setting, new e-mail messages in Outlook are formatted as HTML. If you enable this policy setting, you can set the default e-mail format in Outlook to HTML, Rich Text, or plain text. Users can choose a format other than the default when composing messages. If you disable this policy setting, Outlook uses HTML as the default e-mail format and users will not be able to change it. If you do not configure this policy setting, Outlook uses HTML as the default e-mail format, but users can choose a format other than the default when composing messages.

STIG	Date
Microsoft Outlook 2016 Security Technical Implementation Guide	2016-11-02

Details

Check Text ( C-71657r6_chk )
Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Outlook Options -> Mail Format -> Internet Formatting -> Message Format "Set message format" is set to "Enabled: Plain Text". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\16.0\outlook\options\mail Criteria: If the value EditorPreference is REG_DWORD = 10000 (hex) or 65536 (decimal), this is not a finding.

Check Text ( C-71657r6_chk )

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Outlook Options -> Mail Format -> Internet Formatting -> Message Format "Set message format" is set to "Enabled: Plain Text".

Procedure: Use the Windows Registry Editor to navigate to the following key:

HKCU\Software\Policies\Microsoft\Office\16.0\outlook\options\mail

Criteria: If the value EditorPreference is REG_DWORD = 10000 (hex) or 65536 (decimal), this is not a finding.

Fix Text (F-77575r1_fix)
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Outlook Options -> Mail Format -> Internet Formatting -> Message Format "Set message format" to "Enabled: Plain Text".