I followed also these instructions:
https://www.lansweeper.com/knowledgebase/scanning-exchange-server-mailboxes/
--------------- The Debug-Log:
2020-07-16 12:35:17,292 [DOMAIN\EXCHANGE-SERVER\1] INFO LOGEXCHANGESCANNING DEBUG Connecting using credential: Global Windows for target EXCHANGE-SERVER.Domain.local.
2020-07-16 12:35:17,292 [DOMAIN\EXCHANGE-SERVER\1] INFO LOGEXCHANGESCANNING DEBUG Getting connected domain controller for target EXCHANGE-SERVER.Domain.local.
2020-07-16 12:35:18,964 [DOMAIN\EXCHANGE-SERVER\1] INFO LOGEXCHANGESCANNING DEBUG Connecting using credential: Global Windows for target SVWDC01.Domain.local.
2020-07-16 12:35:18,964 [DOMAIN\EXCHANGE-SERVER\1] INFO LOGEXCHANGESCANNING DEBUG Getting connected domain controller for target EXCHANGE-SERVER.Domain.local.
2020-07-16 12:36:00,989 [DOMAIN\EXCHANGE-SERVER\1] INFO LOGEXCHANGESCANNING DEBUG Executing script failed
2020-07-16 12:36:00,989 [DOMAIN\EXCHANGE-SERVER\1] INFO LOGEXCHANGESCANNING DEBUG Asset with FQDN 'EXCHANGE-SERVER.Domain.local' not found in Exchange server list.
2020-07-16 12:36:00,989 [DOMAIN\EXCHANGE-SERVER\1] INFO LOGEXCHANGESCANNING DEBUG DOMAIN\EXCHANGE-SERVER\1 is not found in the domain's Exchange server list
---------------------Powershell:
Windows PowerShell
Copyright (C) 2016 Microsoft Corporation. Alle Rechte vorbehalten.
PS C:\Windows\system32> Get-ExecutionPolicy
RemoteSigned