No.

As far as I can tell, there is no ctrl+f/F3 style find function in Outlook. You have the search feature, but that behaves differently from ctrl+f.

I've taken to copying email threads and pasting them into Word or Notepad if I need to do a proper find.

^^edit^^

I went out of my way to find out how to do a "find" in Outlook:

ctrl+shift+F for an "advanced" find

F4 for a simple find