The basic info from the rfc:
IMAP is a rich protocol for accessing remote message stores. It provides an ideal mechanism for accessing public mailing list archives as well as private and shared message stores. This document defines a URL scheme for referencing objects on an IMAP server.
The IMAP URL scheme is used to designate IMAP servers, mailboxes, messages, MIME bodies MIME, and search programs on Internet hosts accessible using the IMAP protocol.
The IMAP URL follows the common Internet scheme syntax as defined in RFC 1738 BASIC-URL except that clear text passwords are not permitted. If :<port> is omitted, the port defaults to 143.
An IMAP URL takes one of the following forms:
Read the full rfc at http://rfc.net/rfc2192.html
This was a nodeshell rescue.