If you have a look at your Outlook on the web experience in office 365 you might notices some differences. Microsoft has introduced some changes to the interface as well as added new features.
If you now visit Outlook from your Office 365 web portal and select an email you will see a range of menu options now displayed across the top of the page.
You'll also find new features inside the inbox including the ability to 'pin' messages to the top of the list.
A new option called Sweep allows you to more easily create rules to manage your inbox. You simply select the message to action on and the select the Sweep option from the menu across the top of the screen.
Not only do Sweep rules work like traditional inboxes rules but they also have the ability to run automatically if required keeping your inbox organized when you aren't there or email are flowing in.
The full details about these changes can be found in a recent blog post from Microsoft:
Which you should take a look at to see all the new features they are incorporating. Hopefully by now you should bee seeing these new features in your Outlook on web, if not, they will be rolling out to you soon.