Outlook Rich Text options
Supported on: At least Windows Server 2008 R2 or Windows 7
Registry
HKCU
software\policies\microsoft\office\16.0\outlook\options\mail Options
message rtf format enum - Convert to Plain Text format
->
1
Description
This policy setting controls how Outlook sends Rich Text Format (RTF) messages to Internet recipients. If you enable this policy setting, you may choose from the following for handling RTF messages addressed to recipients on the Internet: * Convert to Plain Text format - Outlook converts the message to plain text format in the default character set. Any message formatting will be lost. If you disable or do not configure this policy setting, Outlook automatically converts RTF formatted messages that are sent over the Internet to HTML format, so that the message formatting is maintained and attachments are received.