If you are a member of an O365 Group (Click here to learn more about Groups), you can subscribe to group messages so they appear in your inbox. It is recommended that you double-check your O365 Groups so you don’t inadvertently miss important messages.
Once you have navigated to your Group within Outlook for Office 365 (https://portal.office.com/outlook), click on the gear icon shown below, then “Group Email Settings”. Make sure there is a check box next to All if you want to receive messages.
For more information, click here: Get started with Office 365 Groups in Outlook