For additional guidance, take a look at our community posts detailing the whole process of migrating from your present platform to Carbonio CE. You will need to help the zimbraMailboxMoveSkipBlobs attribute and disable zimbraMailboxMoveSkipHsmBlobs attribute to the source(NG) server just before initiating the account migration. Now that you have arrange https://www.hostscheap.com/zimbra-migration-service