How to increase/decrease the priority of a rule in Office 365.

Step 1: Sign into Office 365 using the URL http://portal.office.com

Step 2: Click on Admin and navigate to Exchange admin center

Step 3: Scroll down and click on More Features.

Step 4: Click Open under Transport Rules.

Step 5: Click on the Mail Flow tab.

Step 6: Click on the rule you want to change the priority for and click on Move Up or Move Down arrow accordingly