Campaigns requires a Premium or Enterprise level plan
Total tasks are listed in red at the top of the Campaigns to-do list. You may want to use the refresh button in the Sidebar (highlighted below) to ensure all your tasks have loaded. We will only show 500 to-do cards on the Campaigns sidebar at a time. If you have more than that, as you complete tasks, click the refresh button and the remaining tasks will begin to load.
For more information regarding Campaigns, check out our How-to Guide for Gmail.