I'm considering falling back from HS to El Cap (just discovered I can't move on to Mojave, the only reason I jumped up to HS in the first place). My main pain for this fallback will probably be mail. I use POP and keep all mail on my local system, which means I'll need to find a way to move mail from the HS mail folders and files into their El Cap equivalent. Has anyone done this? In a perfect (ie, not-Apple) world this would be easy, but it never is.