Should I prepend all lines with '> '? Is that sufficient? Will it be accepted and understood by all major email clients?
In this case will a original.replace(/\n/g, '\n> ') regex replacement do what I want with the message?
What about the HTML version of the email? Use a big <blockquote>? Just prepending a <blockquote> and appending a </blockquote> will suffice?
Should I, like Gmail and others, prepend a line saying something like "someone <[email protected]> wrote at some time:"?
Plain text and by that I mean: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable just requires ">" to quote the previous message (1 per line).
HTML version - depends on the client you're rendering in.