G DATA Exchange Mail Security installation does not recognize EWS API 2.0

Problem Description

During the installation, a message is displayed on the screen. A red exclamation mark indicates that the installation of Microsoft Exchange Web Services Managed API 2.0 (EWS) is required. The setup can only be terminated.

However, API 2.0 is present on the server.

API 2.0

Possible Solutions

Does the logged-in Microsoft user have an active mailbox?

G DATA Exchange Mail Security can only be installed with user accounts that have an active mailbox in Exchange.

Autodiscover cannot be queried

In most cases, the following procedure is sufficient:


Open the registry editor on the Exchange server.


Find the following key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\MSV1_0


Create there a multi-string value (REG_MULTI_SZ) called BackConnectionHostNames.


Collect the settings of your Exchange Server via: Collecting Exchange Server settings.


Enter the host name of the Exchange server and the internal FQDN (this information can be found in the results of the parameter export created in point 4).

If an external FQDN was configured in the EWS that differs from the internal FQDN, this must also be entered. (This information can be found in the results of the parameter export created under point 4).

Please separate the values by an "Enter" (each entry in a separate line).


Test whether the installation now works properly.

If these instructions did not solve the issue, our technical support for businesses will be glad to help you further: contact G DATA Business Support.

Please provide us with the following information: