I have read several posts about secure authentication using IMAP clients.
My question is:

Is it possible to use Outlook as an IMAP client for Zimbra using an external AD server for username cedentials?
I can make it work using AD username/password without problem, but when windows AD asks (as a security policy) to change password after x months, the user must change it ALSO to Outlook preferences.
I can't find a way to make it works using GSSAPI and do a login to Zimbra getting Windows Authentication token to Active Directory, but you always have to change client configuration