The only server-side rules that Outlook for Mac currently supports is Out of Office. If you are experiencing this issue, upgrade to a newer version.
14.3.2 update\Sent messages are being filtered Within the Get Info screen presented, check the Prevent Nap App box. With Outlook open, use Finder to select the Applications folder, then the MSOffice folder, then holding the Control key down select the Outlook 'O' icon, and select Get Info from the list. Outlook prompts you for password after the computer wakes up after sleep This will also prevent direct GAL lookups. Which will prevent the error from popping up again. Once in place, you can delete the directory service settings. This is a 24-hour old copy of the global address list. It will be listed as ACCOUNTNAME Directory.
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.
