Hi, 

Done this once a few years back but for the life of me cannot remember the mailflow settings!

I have an Exchange server 2003 to upgrade to 2010 then onto O365, the E2010 has gone in with no issues and able to see all of the mailboxes that are in 'Legacy Mailbox' with the exception of the one mailbox that I have moved over to the 2010 server which shows as expected 'User Mailbox' 

From the OWA I am able to send out from this account but when replying I get a bouce back saying:

could not be delivered. The problem appears to be :

-- Recipient email address is possibly incorrect

Additional information follows :

-- 5.7.1 Recipient rejected (R4)

On the E2003 in Routing groups there is the "Routing Group Connector" and shows the 2010 server in the bridgeheads. 

In the Default SMTP Virtual Server, i have also set this to relay to the e2010 server

On the 2010 server I have set a new receive connector to accept mail from the e2003 server. 

I do not have the luxury of turning off the E2003 server as yet, I need the emails to route through the 2003 to the e2010 for a day or two.

Many thanks

Hi wayne,

Thank you for your question.

Did you mean you could send email to others but could not reply to others?

Did the issue occur on all users?

Is reply account located on Exchange 2010?

We could refer to the following steps to troubleshooting:

1.        Use outlook or other browsers to check if we could reply emails
2.        Run the following command on Exchange 2010 to check receive connector:

Get-ReceiveConnector | FL

   3           Collect the email header information and send to ibsexc@microsoft.com for our troubleshooting

If there are any questions regarding this issue, please be free to let me know.

Best Regard,

Jim

Thanks Jim 

I have emailed it through to you 

Wayne

Hi ,

I have received it.

In addition, please answer my question which is in my former reply.

We could refer to the following link to check if the issue persist:

1.        Uncheck Exchange server on receive connector
2.        Restart the service of Microsoft Exchange Transport
3.        Check Exchange server on receive connector

If there are any questions regarding this issue, please be free to let me know.

Best Regard,

Jim