Stop Outlook Calendar email notifications
To stop receiving emails from Outlook Calendar, open your Microsoft Outlook email client and click on the File tab in the top left corner. Click on the Options link next, to open the following Outlook Options box.
Now from the left side select the Calendar tab. Under Calendar options, you will see a Default reminders checkbox. Uncheck the checkbox and click on OK.
Next, click on the Advanced tab, and uncheck Show reminders. Click OK.
Restart Outlook for the settings to take effect.
If you receive a daily email agenda for calendars and task do the following from the Web App.
Under Options > Calendar > Reminders, you will see a checkbox against Get a daily email agenda for calendars and task. Make sure that this check box is unchecked. Save and exit.
If you wish, you can turn off Birthday Calendar as follows.