You can use this module to fetch email from your O365 account.
One of my colleagues had implemented it in his project and it worked fine.
Hope this helps, Good Luck!!
I like Email Connector, also look into this another connector works great for more than just emails
Microsoft Graph Connector https://marketplace.mendix.com/link/component/117007
I happened to find this the other days, having not personally tried yet.
It says: The CAPE Office Plugin allows you to connect your Microsoft Outlook application to your Mendix application and synchronize data between them from Outlook.