Teams supports federated guest access for Gmail accounts using the identity provider framework of Azure B2B Collaboration. Office 365 tenants must first decide if they want Gmail accounts as guests in all or some teams before going down the federation route. Why Teams and not other Office 365 apps? It’s all to do with the endpoint used by the client to connect. If it can handle federation, all good. If not, it’s standard Azure B2B Collaboration.
Microsoft announced a new migration experience from Google G Suite yesterday, which is nice. Under the covers, the venerable Mailbox Migration Service (MRS) does the work to extract mailbox data from Gmail using IMAP4 and moves it to Exchange Online. But after the move is done, there’s still lots of work to do to help users make the cultural change to their new mailbox in the cloud.