One of the annoying new features for me in Office 365/Outlook and outlook.com personal, is creation of an calendar event based on email content. Now this sounds great, if you need the additional automation. But for someone that wants to control what’s in the calendar little more, I need to disable or adjust. Unfortunately, this can’t be changed in the local Outlook app. You need to logon to Outlook web app.
Go into Settings (sprocket) -> Your app setting -> click Mail.
Once in the options, navigate to the Calendar section and click on Events from email. Here you can disable or configure.