Disabling Active Directory User
Follow the steps below to disable an Active Directory user:
Go to Settings > General > Users and Roles.
The Users and Roles page opens in the Users view. Hover over the Active Directory user you want to disable, and then click ellipsis icon in the rightmost column of the row.
In the menu that opens, click Disable.
In the dialog box that opens, click Disable to confirm that you want to disable the Active Directory user.
The Active Directory user appears dimmed in the list of users.