Mailflow on Cross Forest migration

Hi all.  I am working on a cross forest (inter forest) migration project.  Basically I need to migrate all AD user and Exchange 2013 mailboxes from the old AD forest (old.com) to new AD forest (new.com) that is also running on Exchange 2013.  Both the old and new AD forest will be using the same SMTP name space.  This is what I've done:

a) Created the accept domain in new Exchange forest (share.com)
b) Created the shared SMTP name space (share.com) and set it as "Internal Relay"
c) Created the Send and Receive Connector on both old and new Exchange environment
d) Ran the Prepare-MoveRequest.ps1 PowerShell script and set the TargetDevlieryDomain to "new_domain.test"
e) Ran the ADMT User Migration wizard to migrate the SIDHistory (I also excluded all msExch attributes, if I don't exclude them, it will corrupted the account created by the Prepare-MoveRequest PowerShell script)

Checked both the user account attributes, the "TargetAddress" attribute on both of them is set to "xxx@new_domain.test"

This is the result:

1.      Email send from TEST (brand new user in new forest) to TEST2 (migrated account) is NOT working
2.      Email send from  TEST2 (migrated account) to TEST (brand new user in new forest) is working
3.       Email send between TEST (brand new user in new forest) and MYSELF (user in old domain) is working
4.      Email from TEST2 (migrated account) to MYSELF (user in old domain) is working
5.      Email from MYSELF (user in old forest) or external emails send to TEST2 (migrated account) IS NOT working. 
6.       Email from external to TEST (new user in new forest) is working 

So my problem is the migrated user account is not able to accept emails from any body.

 I am seeing this error on the email send from the TEST user in the new forest to this migrated user account (they both reside in the new forest).

You aren't authorized to send to this recipient.<br>For more information about this issue see <a href="http://go.microsoft.com/fwlink/?LinkId=389365">DSN code 5.7.1 in Exchange Online</a>.

Looks like the email is received by the new Exchange server in the new forest, then it got passed over to the old Exchange server in the old forest by using the Send Connector I've configured (there is only one Send Connector in the new Exchange forest, which will pass everything to the old Exchange server).  That seems little bit odd as the recipient is in the same Exchange forest, I don't expect it to send the email out to the old Exchange server 

Then I am seeing this error from the returned email that send from my account (in the old Exchange forest) to this migrated user (in the new Exchange forest)

Remote Server returned '554 5.4.6 Hop count exceeded - possible mail loop'

Any suggestions?  Thanks you.