Focused Inbox and Conversation View
Focused Inbox and Conversation view are two settings that is on by default in Outlook for the web. For most people coming from the full version of outlook this can be confusing. Use this guide to disable the settings and view emails as you are used to.
Step 1 - Open Outlook online: https://outlook.office365.com/mail/inbox
Step 2 - Click on the settings cog in the top right
Step 3 - Click on View all Outlook settings at the bottom
Step 4 - Choose the following settings:
Step 5 - click the close cross in the top right of the settings window