We have a user who is relocating to a different office (London) from our HQ in Boston. The London office is a child domain of the Boston office, all within the same forest. In Boston, we have Exchange 2010 running, but in London we are still on Exchange 2007. I disabled the user's mailbox from Exchange 2010 in Boston, then created a new user account in London. Then I re-connected the disconnected mailbox to the new account in London. Now, when attempting to connect Outlook to the mailbox that lives in Boston, I get the following message "Cannot open your default e-mail folders. Microsoft Exchange is not available. Either there are network problems or the Exchange server is down for maintenance." Any thoughts on how to resolve this?