Comment by ajaykam

It turns out to be a pretty complicated problem. Every single email client and device formats email forwards differently. The technical challenge is to take the input from a fwd'd thread, account for which client it's coming from and then reformat it in a way that makes sense. Not to mention the fact that the text towards the bottom of a forwarded thread (the earliest messages) is messy and can be difficult to comprehend. Parsing garbage and turning it into something useful is a hell of a challenge.