This week on the show, Steve and Paul are joined by Sigi Jagott, long-time MVP and Exchange Server expert, to find out why, and what the best practices are when upgrading on-premises servers to Exchange 2019. And, finally, cross-tenant migrations are possible natively for mailboxes and OneDrive for Business accounts. We discuss and find out if there's any caveats. Teams arrives on Linux (again!), and we discuss Azure AD resiliency and Microsoft's slowing cloud growth..