NOTE: You should have already copied the link location (an iCal URL) from the email before coming here. If you didn't, go back and copy that first!

Start with Outlook already open.

Open the Outlook calendar

Right-click "Other Calendars":

Choose "Add Calendar" and then "From Internet":

Paste the link you got from the email (see, I told you you would need it!):

Confirm your Calendar Subscription:

Appreciation to for their instructions and images - I am giving them full credit for this page.