2010 SP 3 Migration to Hosted Exchange (O365)


We are preparing to migrate our on premises 2010 SP 3 Exchange server, version number, to our hosted O365 environment. I've spoken to one person who mentioned that we are in luck because 2010 SP 3 is oldest of the Exchange versions that will migrate to hosted Exchange. Yet another person I spoke to mentioned that I needed to apply and install all available updates and patches to my 2010 SP3 Exchange server to prepare it for a successful migration to hosted Exchange. Yet another mentions a requirement for SP 3 Rollup 11 (version


Can anyone confirm for me as to which is the correct answer?

4 Replies
best response confirmed by drawson (Contributor)

Hi @drawson 


I'm about to do the same for one of our clients. Most of the documentation I've read just mentions needing SP3 but having it on the latest release to maximize chances of successful migration. My client is currently on 14.3.361.1 RU 18 which isn't too far behind, but I'm going to be updating the latest RU for avoidance of doubt. mentioned that it needs to be update to date to be supported if you are looking to do a express hybrid migration. Might be worth updating anyway just in case things do go down south and you need to call in Support

Hi @HidMov 


Thanks for the reply. Very helpful. What is your standard practice for installing the Exchange 2010 patches? Do you favor installing the latest patch no matter the beginning version? Or do you prefer to install each individual patch building up to the latest? One mention in reading noted it was safe to install the latest update straight away.


We are performing the hybrid migration as we will make the local mailboxes available until they have completely replicated to hosted exchange. Not sure if that is considered express hybrid migration or not.



Hey @drawson 


I've never had a problem jumping from, say, rollup 10 to rollup 25 though it's been a while since I've had a server too far behind. Double check the pre-req's on the latest rollup just to make sure there are no gotcha's, but generally should be ok to go to the latest.

Cool @HidMov! Thanks again for your input. I'll confirm what the pre-reqs say.