I know it's late with this migration but my company is finally doing it. I've got EX2010SP1 running. I created a new mailbox user on 2010 and sent mail to a 2003 mailbox. Currently i cannot send 2003 to 2010. i have no smart hosts in 2003 smtp. i tried removing the routing connector and putting a new one via this guide i've been following at the powershell section:
My question, since i can already send mail out 2010 to 2003 could i go one more step which would be to add my mx record for this new server on Network Sol and get external mail sending/receiving, could i proceed move the mailboxes from 2003 -changing the respective outlook profiles to point to the new server? Im coming up to the weekend if this would work i can just bypass figuring out 2003 to 2010 message flow.