We are testing a hosted Exchange environment and have run into a snag that I cannot figure out. I am not the main admin for the internal Exchange 2003 box so that is part of the challenge. In order to support users in both environments during the transition, the hosting provider suggested using their split domain option and setting up a forwarding address (alias to the hosted server) on the mailboxes moved to the hosted environment. I can: 1. Send a test message from my gmail account to the alias address successfully. (jblow@domain.serverdata.net) 2. Send a test message from an internal mailbox on our Exchange server to the now hosted address succefully. (jblow@domain.net) But if I send from my gmail account to the correct domain email address (jblow@domain.net), the message never arrives. If I use the message tracking center on my Exchange server I see the missing email with an NDR after the SMTP: Started Outbound Transfer of Message. The second test sent internally shows a successful outbound transfer to the hosted environment. Does any one have any idea of what may be causing this? Its been a while since I dug into an Exchange 2003 box. I can't remember where or if I can dig up the NDR since it is never sent to my gmail account. Thanks! Eric

is jblow@domain.net the new hosted provider domain? Go to https://testexchangeconnectivity.com and do an inbound SMTP test and post the results.James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

jblow@domain.net is our current domain and is hosted internally at the moment, but we've setup mailboxes on the hosting provider with those addresses and enabled a split domain configuration. Email sent to jblow@domain.net is directed to our mail server, which then forwards to an alias pointing to the hosted system. The split domain allows mail sent from the hosted domain to be sent to the correct MX record until we are fully migrated over to the new environment. Hope that helps!

Are you sure you're set up properly to relay for the hosted domain? Exchange will see any email that is neither from nor to one of your accepted domains as being an attempt to use it as an open relay.[string](0..33|%{[char][int](46+("686552495351636652556262185355647068516270555358646562655775 0645570").substring(($_*2),2))})-replace " "

How are you doing the forwarding exactly, from the mailbox forwarding to a contact that represents the aliased address? The hosted provider could be rejected based on SPF validation which fails when forwarding occurs. I would check with your hosted provider as well. Messages that are sent through Exchange 2003 to an external messaging server are blocked by Sender ID checking http://support.microsoft.com/kb/915863James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

That is a good point. Its been a while since I've touched Exchange 2003 and I am not the regular admin on the box. How can I check or allow relaying for testing? Thanks!

I have setup a contact within AD for the user's hosted email address. For example, her real address may be jill@mydomain.com and the hosted provider has an alias to our hosted Exchange such as jill@mydomain.serverdata.net. I can send email directly to that alias and it arrives in her mailbox and if I send an email from our exchange server to jill@mydomain.com, the email is correctly forwarded to the hosted mailbox. It is only when I try sending from an external mail server such as gmail or yahoo. me@gmail.com to jill@mydomain.serverdata.net (hosted) = works me@mydomain.com (Internal) to jill@mydomain.com (hosted) = works me@gmail.com to jill@mydomain.com (hosted) = fails Thoughts??

It's been so long since I touched a 2K3 server I don't remember any more, but I know that out of the box it's not going to want to relay mail from one external domain to another without being told to.[string](0..33|%{[char][int](46+("686552495351636652556262185355647068516270555358646562655775 0645570").substring(($_*2),2))})-replace " "

To me it seems like SPF rejections. Verify with your hosted provider.James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

But I am alllowed to forward email to the hosted Exchange mailbox IF the sender originates on OUR Exchange server. It only fails if the sender originates External to our Exchange server. If the hosting provider is checking SPF wouldn't it fail for both senarios? Internal Sender -> Our Exchange Server->Frwards to Hosting Provider (Host provider sees the correct originating IP for the SPF) - WORKS External -> MX -> Our Exchange Server->Forwards to Hosting Provider (Hosting provider sees the correct originating IP for the SPF) - FAILS Or did I miss understand your comment? Thanks, Eric

Same here and I gave away all my reference books :)

It could still be SPF. The recipient server is going to look at the domain of the From address. If it's a gmail address, your server isn't going to be listed as authorized to be sending email for that domain. Hopefully, the hosting company will have told their servers to ignore checking for mail from your server, but.....[string](0..33|%{[char][int](46+("686552495351636652556262185355647068516270555358646562655775 0645570").substring(($_*2),2))})-replace " "

Interesting point! They've done a lot of hosting and transition so hopefully they have a solution if that is the case :)

Hi, Is there any update?Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Thanks Gen Lin-MSFT

I have dug and pulled as many logs as I could find and have left it up to the main consultant who put the Exchange environment together. Hopefully they can figure it out!