A) You exhausted the daily message limit
To fix this,
1. Click on the LeadMagicX icon next to the search bar at the top right to open LeadMagicX (If you don't see it, click on the puzzle icon next to the address bar on the top right and Pin LeadMagicX)
2. Click "Settings"
3. Increase the daily message limit
4. Save
B) Your chrome browser is closed
For the queues to send out on its own, your browser has to remain opened.
C) Your computer mode is Sleep
For the queues to send out on its own, your computer has to be on. When computer is under Sleep mode, all programs get suspended. You may disable Sleep, Hibernation and Hybrid Sleep. That is the only way programs keep running.