have an existing exchange 2007 server that is the authoritative exchagne server for a couple domains, currently we have an icewarp server also in the AD forest handling mail for another email domain. We are replacing the icewarp server with exchange 2010. So what happened was after installing exchange 2010, it pulled all the mailboxes from the 2007 server as well. I added all the current icewarp users to exchange. Now anyone from the 2007 server can't send mail to the 2010 server, i assume because its trying to send through the 2010 server yet? we aren't ready to go live yet on the 2010 server, how can i keep mail going to icewarp until ready? remove the mailboxes of those users for the time being?