By default, the Zimbra admin port is 7071. Cloudiway migration platforms requires to hook up with the admin platform in order to retrieve facts. You will need to disable the zimbraMailboxMoveSkipBlobs attribute and help zimbraMailboxMoveSkipHsmBlobs attribute to the supply(NG) server right before initiating the account migration. Customize configurations, Tastes, and https://www.hostscheap.com/zimbra-migration-service