Not a specifically Python-related post, although most of my mailing list activity is Python-related. Anyone who’s spent a more than negligible amount of time following any of the Python lists will have encountered the “We Bottom-Post Here” reaction to posters who top-post. Personally it makes sense to me, altho’ I do sometimes feel that people are too forthright about things of this sort.
That said, my experience among practically all my colleagues, friends and relations is that bottom-posting or inter-posting (ie snipping segments of an email and replying to them immediately afterwards) is downright confusing. You can blame the phenomenon on the default behaviour of certainly commonly-used email clients if you like. But I’ve had several people reply to me in puzzled tones along the lines of “Why do you put your comments under my comments like that?” or even “I think you pressed the Send key too soon…” when I’d replied at the bottom of their email rather than at the top where they expected it.
Ultimately, When in Rome… I think bottom/interposting makes more sense, but if it makes less sense to my correspondents then I view that as my problem and not theirs.