Is there a way to keep Exchange 2013 from converting HTML message bodies of incoming messages into RTF?

I'm looking at a message that was sent to an Exchange 2013 user that has this at the top of the message body (PR_RTF_COMPRESSED):

{*\generator Microsoft Exchange Server;} {*\formatConverter converted from html;}

The message body is in pure RTF. I expect to see HTML wrapped in RTF, which is what I want.

I've looked at "Set-MailUser -Identity blah -UseMapiRichTextFormat Never", but that doesn't work for a user with an Exchange mailbox and I think it only applies to outgoing mail anyway.