- While for 20, and not 2013, it refers to the proxy preventing access to the Exchange server directly.

Eventlog shows proper working, any Powershell command tossed shows a good generation of the OAB. If I force a download of the OAB on the client however, an error is tossed: (0x8004010F).

So I assume the clients that look at the OAB (if using cached mode) will be looking at an older copy of the OAB that doesn't have the new user in it, and are unable to actually download the new OAB.https://support.microsoft.com/en-us/help/939765/error-0x8004010f-occurs-when-outlook-synchronizes-an....

After you install Dynamics 365 for Outlook, you have to set some options so that users can send and receive email from Dynamics 365 for Outlook and to specify what data is synchronized.

Users who log on locally to a device that has Microsoft Dynamics 365 for Outlook installed can potentially access Dynamics 365 data stored locally.

Microsoft Dynamics 365 for Outlook enables access to the same data through Microsoft Outlook as the Microsoft Dynamics 365 Web client.

Dynamics 365 for Outlook is for Microsoft Dynamics 365 users who need access to Dynamics 365 data while they are using the familiar Outlook application.

Shared use of a device running Dynamics 365 for Outlook is not supported.

More information: Help & Training: Set personal options that affect tracking and synchronization between Dynamics 365 and Outlook or Exchange Help & Training: Set address book options in Microsoft Dynamics 365 for Outlook For upgrade information, see Upgrade to Microsoft Dynamics 365 for Outlook.

Internal Url : https://webmail.mydomain.com/OABInternal Authentication Methods : External Url : https://webmail.mydomain.com/OABExternal Authentication Methods : When checking the GUID for the OAB (Get-Offline Address Book | fl) and using this in both the autodiscover and webmail, along with the GUID resulting in the following URL's, both display the contents of the file properly:/oab.xml"/So the OAB is generated properly (I can see the correct date and time of the last generation on the actual file on the server, both on a forced update, aswell as the eventlog on the server), and is accessable through the URL I'd expect.

I'm just not sure Outlook knows exactly where to look.

3 - All 4 present databases refer to the OAB as the '\Default Offline Address List (Ex2013)'.