By Default user gets email notification for task assigned to him and any calendar event (create/ update/ delete) assigned to him. To enable/disable getting email notifications for task and events follow the steps below:
1. Go to the Account Settings icon highlighted in the image below.
2. The second tab on the Account Settings page is Email Notification, select that tab.
3. Three check boxes are available on the page for enabling and disabling email notification when the task is assigned, event is created/updated or an event is deleted.
4. Check /Uncheck the options if you want to enable /disable email notifications.
5. Click Save to save the settings.
Go to the next article : Account & Password Setup