I have a issue. I want to start using zimbra but in a phased manner. I have few users who doesn't have relay to outside. I want to use them in zimbra OCS edition. And the others be with exchange. Is there any steps in which this can be one. Are there any changes we need to make in DNS. During installation of zimbra. How can we make these users of domains be recognised by zimbra. As windows password should be password of mail too. and use the same Exchange MAPI.