Hi, I currently have one Exchange 2003 server running on Windows Server 2003. I have two domain controllers also running Windows Server 2003. We use OWA and POP3 access for some remote users. I am planning to migrate to Exchange 2007 SP1 running on Windows Server Standard 2008 x64. This will be a clean install of Server 2008 and Exchange 2007. I've prepared the Server 2008 according to the Technet article on Exchange 2007 Prerequisites on Windows Server 2008. Once I've installedExchange, I will move mailboxes to the new server and eventually remove the old server. I am keen to avoid losing any functionality (OWA, POP3) during the changeover period. Are there any particular steps I need to take to ensure this works OK? Thanks, John

Hi John, Although written with Exchange 2007 on Windows 2003 in mind, my E2K7 transitioning articles seriesshould help answer those questions: http://www.msexchange.org/tutorials/Transitioning-Exchange-2000-2003-Exchange-Server-2007-Part1.html If not let me know.

Thank you Henrik. I will work through your articles and ask further questions if necessary. John

By installing the Hub Transport Service on the new Exchange 2007 SP1 server, I won't be interfering with the current delivery and sending of mail on the Exchange 2003 server before I move mailboxes to the new server? Thanks, John

Nope you configure a routing group connector between legacy Exchange and E2K7 to establish mail flow. And inbound/outbound maill to/from the Internet won't be changed before you do so manually. One thing to keep in mind is that you should make sure not to have any smarthost specified on the SMTP virtual server, but instead use a SMTP connector for outbound mail. Otherwise you'll have problems sending mail from a legcy mailbox toan E2K7 mailbox.

Hi Henrik. Installation went fine or so I thought. I moved one Mailbox from Exch2003 to Exch2007 and tried to send messages either from 2003 to 2007 or from 2007 to 2003 and even 2007 to 2007.None of the messages are delivered. The ones on the 2007 server don't even leave the Outbox. I have received one NDR for a message sent from 2003 stating: You do not have permission to send to this recipient. For assistance, contact your system administrator. <exchange.internaldomain.local #5.7.1 smtp;530 5.7.1 Client was not authenticated> I've tried to find out everything about the connectors that are setup during installation for the 2003 server but everything seems OK. How can I troubleshpoot this issue to get mail working? Thanks, John

I guess this issue only occurs when you submit messages via POP3 clients and that OWA works as expected?

Henrik Walther wrote: I guess this issue only occurs when you submit messages via POP3 clients and that OWA works as expected? Hi Henrik Tried OWA both from the mailbox on the Exch2007 server and from a mailbox on the Exch2003 server. On Exch2007, nothing seeems to happen at all. WhenI click on send the message disappears and doesn't appear in Sent Items. From Exch2003, message is sent properly, but immediately a NDR arrives: Your message did not reach some or all of the intended recipients. Subject: Test from Johnvan OWA Wed 8:05 am Sent: 10/12/2008 7:57 AM The following recipient(s) cannot be reached: Mailbox Nameon 10/12/2008 7:57 AM A critical function required for the transfer or delivery of the message was not supported by the originator of the report <exchange.internaldomainname.local #5.3.3 smtp;500 5.3.3 Unrecognized command> Thanks, John