When performing the mailbox test the following pop up error is received: "8004860A(598BA0F) It is not possible to check the mailbox configuration."
MAPI encryption for accessing Exchange databases has been activated. Or the Mailbox his hidden from the Global Address List (GAL)
Unkide the Mailbox so you can see it in the Global Address List
If the MAPI encryption for accessing Exchange databases has been activated, the QCS service account is not able to access the service mailbox to retrieve the free/busy information. In addition, if a mailbox test is performed in the QCS properties, a pop up error box is activated with the message "8004860A(598BA0F) It is not possible to check the mailbox configuration." Selecting the Advance button gives the possible reasons which appear to be related to permissions, server availability or mailbox availability.
This can be confirmed by running the following Exchange Powershell command on the server where the service account mailbox resides.
Get-MailboxServer server_name | fl name, mapiencryptionrequired
If MAPI encryption has been turned on the PowerShell command will return the following:
Name : server_name
MAPIEncryptionRequired : True
MAPI encryption is enabled between clients and the server they access for their mailboxes. The PowerShell command only activates MAPI encryption on the Exchange server in which it has been run.
The following Powershell commands are used to configure this feature:
To turn MAPI encryption on - set-MailboxServer server_name -mapiencryptionrequired $true
To view the status of MAPI encryption - get-MailboxServer server_name | fl name, mapiencryptionrequired