Most who know Exchange are familiar with the feature that allows a user to open parts of his mailbox to certain delegates. Accessing the delegated folders is pretty straightforward if you use Outlook MAPI. What is less commonly known is that in the case of email folders it is possible to access a delegated folder using IMAP with your own username and password without Outlook. The trick is in the way you specify your username.

user then password opens your own folders
domain\username\otherusername opens the folders of the other person who made you a delegate

This is pretty simple to implement in Outlook IMAP or Eudora and I know this to work in those clients. I just can't get it to work in Chatter. I get a "Bad Login" error and what's worse is that my other working inbox stops working until I delete the other mailbox.

This is the configuration I am trying (I am abstracting but the characters are as they would be, the folder names are real and the server is the same in each case)

First Chatter account (works until second is added):
folder name: Exchange
imap server: server.domain
password: something
Folder: Inbox

Second Chatter Account (not working in chatter):
Folder name: Richard
imap server: server.domain
username: domain\\
password: something
folder: Inbox

TIA for any pointers/suggestions