Hi Richard, I don't see any problem because I'm reading this mailing-list from a MUA that's mostly text-only and doesn't try to use variable-size fonts, but looking at the HTML you send I see:
> <div class="gmail_default" > style="font-family:arial,helvetica,sans-serif;font-size:small"> repeated several times. I have no idea why your MUA puts it there, but I suspect that's the reason some of the readers here find your email's messages to be hard to read: your mail specifically asks for `font-size:small`. This might qualify as a bug in your MUA (it can make sense to require a small font for some parts of the message, but it seems this style applies to the whole message, which makes no sense), tho maybe it's due to some particularity of your configuration, or of the way you use your MUA's editor. Stefan