On Sun, Jul 31, 2022 at 01:47:06PM -0400, Kurt Hackenberg wrote: >I agree there should not be a space after the '>'. The trouble is, >that space is ambiguous: software can't tell whether it's part of the >quoting or part of the original message.
I spoke too soon. Now I've experimented with Mutt and Thunderbird[1] and read some Mutt code, and have a better idea what's going on. That space in $indent_string confuses software less than I thought. $indent_string is only used in a format=fixed reply; it's ignored for format=flowed replies, which are required to use ">" (no space). A fixed block of quoted text with a space after '>' would cause trouble if the message containing the quote is quoted in a flowed reply -- but not much trouble. Those quoted lines would be fixed -- would not end with a space -- so would not be re-wrapped. I think the code constructing the quote in the flowed message would interpret that space as space-stuffing, and delete it, but that's mostly harmless. When no flowed-text message is involved, I don't think there's any formal rule about space or no space, and text won't be re-wrapped or modified. A mail reader might misrepresent the quote levels and cause confusion about who said what, but Thunderbird seems to understand it. (Thunderbird replaces >>>... with multiple colored vertical lines, and, in fixed text, accepts '>' with space as a quote marker.) [1] Mutt and Thunderbird are the only mail readers I know of that implement text/plain format=flowed. Mutt only implements it partially; it relies on an external editor to do some of it. Thunderbird has its own editor.
