Are you talking about the quoted text in the email body? That is in order or essentially reverse ordered depending on the choices of the individual quoting a previous mail.
When you choose to quote below reply, the topic's chronology is in order. When you choose to use the Outlook/Microsoft idea of quoting after the reply, then it appears in reverse order. You and your correspondents build the document (which is a single text document or web page) you expedience in some actions results in you wanting the product to somehow resort your text. I am sure they will consider it.