Exchange 2010, Users cant send or receive email after migration

I just finished my install of Exchange 2010 today and after jumping through many hoops of fire to get the software installed I have an issue. I migrated 2 test users from our 2003 exchange server and after the migration was complete I sent the users a few email messages from a mailbox on the 2003 server. The messages never got to the 2010 exchange mailboxs, and seem to be in the Queue listed as "Messages with an unreachable destination". Also when sending from the 2010 mailbox, the messages never arrive on the 2003 users mailbox. So there seems to be some sort of routing issue. Any ideas would be helpful.
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Please make sure you have bidrectional routing group connector created.if not create it and if yes remove it and create it again.
On Exchange 2010 run get-routinggroupconnector.



On Exchange 2003 in SMTP vertual Server if you have any Smarthost please remove it and use internal DNS.
Make sure Exchange 2003 can telnet 25 of Exchange 2010 and vice-versa
Make sure Exchange 2003 can ping Ex 2010 and vice-versa

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johnrkeanAuthor Commented:
I added the RoutingGroupConnectors, one of them has my 2003 exchange as the source and the 2010 as the target. Then I created another connector but made the source 2010 and the target 2003. As soon as I did that the user's mailbox started blowing up with all of the messages in the Q. That seems to have been the issue. Thank you for all the help in solving that problem.
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