How to attach e-mails to new e-mail?


New Email
How to attach received e-mails (from inbox, sent box, or trash) to a new e-mail that I am drafting? From the attach button easy to attach pics or docs from My Documents, but how to access the e-mails to add as an attachment?
My e-mail used to be AT&T, but they turned it into a Yahoo account a few years my e-mail address is still an address.