You can automatically receive email notifications when you server storage reaches certain threshold from the System > Storage screen:
1. Set the Email minimum space threshold. This settings specifies when you will receive the notification email. Note that, this setting must be equal to or greater than Minimum space threshold. If you enter 0, you will disable the email notification.
2. You can set who will receive the email notification in the Email addresses to be notified on storage limitations field.
3. You can disable the notifications temporarily by clicking the Disable notifications for 12 hours button.
4. Click the Save changes button to save the changes.