The new version of OWA boasts new abilities for owners to manage Office 365 Groups. The new UI is pretty slick and a welcome upgrade to the previous capabilities. You’ll still need to revert to PowerShell to manage some aspects of Office 365 Groups, but not as many times as you used to.
Despite the age of the protocols, you can cheerfully connect a wide range of IMAP4 and POP3 clients to Exchange Online. If you do, you might need to consider how to handle calendar appointments, and if you want to use iCAL, you’ll need to make some adjustments with PowerShell.
The ThirdPartyFileProvidersEnabled setting in OWA mailbox policies controls if Exchange Online mailboxes can access services like Drop and Dropbox for attachments. Office 365 tenants need to decide if they want to allow this kind of access. There’s both good and bad in the feature, but it’s easily turned off if you feel the need.