So we at Sumatra are very happy to announce in 2022 (entering our third year of the COVID pandemic!) that we have successfully field-deployed a Kerio Connect to Office 365 full-state calendar migration tool!
A couple of screen shots of the capability:
We ran it in December 2021 at a law firm in the Boston, Massachusetts area!
Many thanks to all involved there for their testing and attention to detail that made it a success!!
The user IDs from legacy Kerio are mappable to new IDs on Office 365.
We of course re-create meetings as meetings with guest lists and responses so it's a huge level above any export-import methods you see out there.
And we can also preserve resource bookings in a Kerio to Office 365 migration -- though our client did not migrate resources so we're looking for a partner to prove that works as well.
Details on request -- please just drop us a line. Please also let us know the specifics of how many users you'd like to migrate.