This notification is sent when the queue of your scheduled posts for one or more accounts is empty. This setting can be turned off via the Crowdfire web app.
To turn the Queue Empty notifications off:
  1. Log in to your account at www.crowdfireapp.com from your desktop or laptop
  2. Select the gear icon (settings) on the top right corner of your screen
  3. Under the Channels, click on the account for which you want to turn the notifications off
  4. Click on the toggle switch next to Queue Empty Notification to turn the notifications off
If you wish to turn notifications off for all the connected accounts, you will have to turn them off individually for each connected account by following the same steps as above.