Moving Exchange 2003 to 2010 emails not flowing
I'm in the process of migrating Exchange 2003 to 2010. All is going well but I've noticed emails from users still on 2003 box are not sending to users on 2010 box but there is no problem sending from 2010 to 2003. I've deleted and remade the routing group connector but it not made any difference, also which I suspect is connected is when users on 2003 send emails externally they are queued on the 2003 box for about 10-15 minutes before sending via 2010. Both boxes have the same smart host configured.
What I’m I doing wrong?