Why can't I define a Mail Rule to send empty content messages to Junk?

MacBook Air, Sequoia 15.5, Apple Mail with Junk filter settings set to Enabled and default options selected. I started to receive large amounts of spammy mail. 99% of it came from the .de domain, so I set a Rule to send msgs with "From" "contains" ".de" to the Junk folder. Mail (junk) indicates that these msgs have no [body] content, yet they have remote content. Now, I'm getting more spam from random domains, so I want to define a Mail Rule to send msgs by "Message content" "contains" "[null]" (meaning "is empty") but there is no option to do so. Does Apple Mail determine that the msg has no body content, or does it sequester the body content remotely based on the Junk filter settings and thus, remote content exists? Now, I have 21 Rules to handle most, not all, of the spam mail that I'm getting. If I could just set one Rule to send empty content msgs to Junk, and then select "Filter junk mail before applying my rules" in the Junk settings, that would catch all of it. I was told that it was possible in the past to send empty content msgs to Junk, but no longer. Can someone please explain?