Hello, Thanks for Falko's howto on setting up virutal users: http://www.howtoforge.com/virtual-users-domains-postfix-courier-mysql-squirrelmail-centos-5.3-x86_64 Just want to ask (if any one has this experience) --- if I follow this guide to set up virutal users on a production environment of ISPConfig2.X, will the result be a) Failure ; or b) all existing users account will become un-usable, and must be converted to virutal users before the system can handle ; or c) the system will be able to support both "real" users and "virtual" users at the same time ? Anyway if there is no one having this experience I will try it by myself asap. Thanks.