My company is currently in the middle of updating our Exchange from 2003 to 2013. Since there's no direct path, we're going through Exchange 2010 first. Currently, we have servers at our head office, as well as 2 other remote locations, all using different URLs for OWA/Outlook.
Our plan is to consolidate the remote locations to an Exchange environment at our datacenter, and leave an Exchange server at our head office for those users (can't move them to the datacenter because we have crappy internet).
We'd like to stop using separate URLs for each server, and simply have one URL that users at both the datacenter and our head office can use, which will route them properly to the location that their mailbox is hosted. What would the ideal solution to accomplish this be?