Workaround: Outlook 2011 SP1 (With autodiscover record in place) will download an offline address book.
We have contacted Microsoft about this and unfortunately, they do not have any working solution. When the Directory Server (LDAP) information is configured correctly in the account settings, the functionality is enabled for directory lookups, but Outlook will repeatedly display an error code 17768.
This article describes some known issues affecting Outlook 2011, Outlook 2016 and Outlook 2019 for Mac.
