We have introduced an Exchange 2013 server into our environment. We updated our firewall to point incoming HTTPS services away from our 2010 CAS to the new 2013 server. Everything worked fine, OWA logins for Exchange 2010 mailboxes redirected from Exchange 2013 OWA to Exchange 2010.
ActiveSync did not work through 2013 for Exchange 2010 mailboxes. Does the "External URL" need to be updated within Exchange 2010 for this to pass through? Could someone walk me through possible modifications that will need to be made within our environment to pass this ActiveSync traffic successfully?