回帖：问题解决了，参考cloudiffic.com/error-during-setup-moderecoverserver
在ad上用adsi，定位到Configuration partition –> Services -> Microsoft Exchange –> Org Name –> Administrative Groups –> Exchange Administrative Group–> Servers –> Mail-server
属性定位到msExchEdgeSyncCredential内
移除msExchEdgeSyncCredential内的项目（通常为3个）
OK