It probably doesn't matter either way, as it doesn't seem like people do more than skim emails. They won't scroll down to read interleaved replies--Outlook/Entourage's text-formatting doesn't help--nor will they even scroll down if your top-post goes past the default view.

If you can't say it all in three short paragraphs, you either have to spread it out over a few more focused emails, spoon-feed over IM, or--horror of horrors--meet in person!