This policy setting allows you to control the format in which email messages are synchronized. This policy is typically used ...

"This policy setting allows you to control the format in which email messages are synchronized. This policy is typically used to reduce network bandwidth by forcing messages to be downloaded in Plain Text format.  If you enable this policy setting, then you can select the message format in which messages are downloaded. The option on the device that allows the user to select the download format is disabled.  If you disable or do not configure this policy setting, then the user can select the default format in which messages are downloaded."