I was able to migrate and merge a mbx from the on-prem source Exchange to a target mbx in O365. The target mbx was moved from the target on-prem Exchange to O365 prior to the source to target migration.
I was able to migrate and merge a mbx from the on-prem source Exchange to a target mbx in O365. The target mbx was moved from the target on-prem Exchange to O365 prior to the source to target migration.