I am transitioning from exchange 2007 ( server 2008) to exchange 2010 ( server 2008r2) I wanted to make OWA the same name to be able to use the same SSL, but when I move users over to the new server, they are getting an error stating that the name on the security certificate is invalid or does not match the name of the site.. Do you want to proceed. clicking yes or installing allows them in, but it keeps popping back up. I was hoping to move users over slowly then move all the smartphone users last that are using the owa address to get mail on their phones. Then just change the IP of the new server to be the same as the old. Is that not possible to keep the same address for OWA or am I doing something wrong?