We have recently managed the largest migration known to date from Microsoft Hosted Exchange to Office 365 (hundreds of thousands of mailboxes) in collaboration with Ricketts Corporation. It has been very hard and intensive for everyone involved but what has been amazing is how well Ricketts Corporation consultants know what to do, how well they know how to do it and, overall, how well they have done it. Honestly, chapeau! Thank you so much!
David Gonzalez, Services Development Manager at Acens and head of Project Management in Office 365 project.