Controlling Task-Assignment Notifications
From AgileApps Support Wiki
By default, an email notification is sent out to the owner when a new Task is created, or when you reassign an existing Task to someone other than yourself. That behavior is defined by Event Rules, which can be turned off or conditionalized, as desired.
To control the behavior of task-assignment notifications:
- Go to > Customization > Objects > Tasks > Business Rules
- In the Event Rules tab, select On Record Created.
- The task-notification rule that appears. Click the On/Off button to disable it, or click the rule to add conditions or other actions.
- While still in the Event Rules tab, select On Record Owner Changed.
- The task-notification rule for this situation appears. Disable it or click the rule to add conditions or other actions.