Outlook Rich Text options must be set for converting to plain text format.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-251867	DTOO344	SV-251867r812967_rule		Medium

Description
Outlook automatically converts Rich Text Format (RTF) messages that are sent over the internet to HTML format, so that the message formatting is maintained and attachments are received. This setting controls how Outlook sends RTF messages to internet recipients.

STIG	Date
Microsoft Outlook 2016 Security Technical Implementation Guide	2022-03-11

Details

Check Text ( C-55327r811190_chk )
Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Outlook Options >> Mail Format >> Internet Formatting "Outlook Rich Text options" is "Enabled: Convert to Plain Text format". 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 Message RTF Format is REG_DWORD = 1, this is not a finding.

Check Text ( C-55327r811190_chk )

Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Outlook Options >> Mail Format >> Internet Formatting "Outlook Rich Text options" is "Enabled: Convert to Plain Text format".

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 Message RTF Format is REG_DWORD = 1, this is not a finding.

Fix Text (F-55281r811191_fix)
Set the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Outlook Options >> Mail Format >> Internet Formatting "Outlook Rich Text options" to "Enabled: Convert to Plain Text format".