If you’re free on your calendar, you can get automatically accepted for meeting invitations. Hassle free if you don’t like responding when you’re already free. Here’s how to do it:
On your Outlook, click on File on top tab.
Select options from the menu.
A new Window should appear, select Calendar.
Scroll all the way down until you see Auto Accept/Decline and click on it.
Tick boxes that applies to you and then Click OK.