Now, Gmail lets you add emails as attachment without downloading them

You no longer have to forward multiple emails with Gmail's latest update that lets you send email as an attachment.
As the official blog notes, users will be able to attach emails to other emails in Gmail without having to download them first. To insert emails in a new thread, simply drag and drop them into the draft window.
You can also insert emails by selecting the emails and then 'Forward as attachment' from the overflow menu. The feature is being rolled out gradually and users will know the availability when they see the forward as attachment option. Read More