Exchange 2010 co existing with Exchange 2003


I am rolling out some EXchange 2010 servers and in the meantime still have my Exchange 2003 servers. I have setup my bidirectional connectors and can send an email externally from exchange 2010 mailbox and receive back, but not send any emails from an Exchange 2010 mailbox to an internal mailbox on Exchange 2003. It sends and leaves the outbox and never arrives?

any ideas
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David CarrCommented:
Do you have connectors to point to 2003 configured in 2010?
monarchitAuthor Commented:
NetoMeter ScreencastsCommented:
Could you elaborate on the bidirectional RGC that you've created? Posting the result of
Get-Routinggroupconnector | fl 

Open in new window

would be even better. Normally, an InterOP RGC is created automatically, unless you've had to restart the setup (ex. failed checks) and chose the option "use previous answers".
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Mohammed TahirMicrosoft Exchange and O365 AdministratorCommented:
Also check the below points:

1- Ensure you are successfully able to telnet both servers from other one on port 25.
2- Try by disabling any Anti-virus running on your exchange servers.
3- What happen when sending via OWA?

Simon Butler (Sembee)ConsultantCommented:
Start by recreating the routing group connectors. Seen those cause these problems many times.

Then check that the SMTP virtual server on Exchange 2003 doesn't have any connection restrictions applied and is as close to default as possible.

Do the messages show in the Exchang 2010 or 2003 queues?

monarchitAuthor Commented:
This was an IPV6 issue and by disabling it at hardware level resolved the issue

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monarchitAuthor Commented:
This was the solution
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