1. Open a web browser and navigate to http://mail.office365.com
2. Log into your email account
3. Once you have logged in click on the Gear icon at the top right of the page.
4. On the Settings menu that has just opened click on "Automatic replies"
5. Once the "Automatic replies" menu opens you can now set a variety of features
-Send replies only during a certain time period
-Block your calendar for the set period you will be out of the office
-Automatically decline new event invites during your out of office period
-Decline and cancel meetings during your out of office period
-When setting an out of office message make sure that you set both the reply for "inside my organization" and "outside my organization"