This is an email alert which can be configured under "Alert" section in the CommServe GUI
Once you are in the alert section you should see the following:
- Name - XXX_Content Indexing - Low Disk Space
- Alert Category - Operation
- Alert Type - Event Viewer Event
You can disable the alerts for specific Client.
However there is always a reason why you get an alert. In this scenario it is reporting the Index Location has reached 80%, if this is an active Search/Index Node I would recommend to investigate further. However if this is a VM Search Only Node, then disabling the alert should be fine