I have setup a new Exchange 2007 server with the Client Access Role. I am attempting to access an Exchange 2003 mailbox via IMAP. I have enabled IMAP on the Exchange 2007 Client Access Server and I have started the IMAP service. Connections are successful but I can't authenticate. Here is the error dialog Using Outlook Express: LOGIN failed. Configuration: Account: exch-hub1.mydomain.com Server: exch-hub1.mydomain.com User name: wtholmes@xxxxxxxxxxxx Protocol: IMAP Port: 993 Secure(SSL): 1 Code: 800cccd1 I am able to access my exchange 2003 legacy mailbox via OWA through the same server. I am also able to access the legacy mailbox using an Exchange 2003 Front-End Server. Any assistance appreciated. Thanks Bill