An updated internet-draft is available from the IETF. This draft is a work item of the Enhancements to Internet email to support diverse service environments Working Group of the IETF.
Abstract: «This document describes the Lemonade profile to allow clients to submit new email messages incorporating content which resides on locations external to the client (”forward without download”). The Lemonade profile relies upon extensions to other protocols; specifically URLAUTH, CATENATE, Lemonade Command Extensions in the IMAP protocol [RFC3501] and BURL in the SUBMIT protocol [RFC2476]. In addition, the Lemonade profile contains Lemonade Command extensions for quick reconnect and media conversion.»