We moved from in house exchange to hosted exchange with Intermedia 3 years ago. It was pretty straight forward. I was able to sync my mailbox store with theirs and let it sync for a week before changing my mx record. I can't seem to find any info on moving from a hosted to hosted solution. Anyone else done this? We have 250 boxes, Intermedia is currently on exchange 2010 and MS 365 will be exchange 2013.