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 URLAUTH extension to the Internet Message Access Protocol (IMAP) (RFC3501) and the IMAP URL Scheme (IMAPURL) (RFC2192). This extension provides a means by which an IMAP client can use URLs carrying authorization to access limited message data on the IMAP server. »
«An IMAP server which supports this extension indicates this with a capability name of “URLAUTH”.»