Hi, We are currently in the middle of rolling out Exchange to our whole company, we are using QSS Exchange Connector to retrieve e-mails from our current POP3 server and forward them to Exchange. This is all working properly and I don't believe this is causing any issues, the problem is below: infrastructure@mydomain.com #550 4.4.7 QUEUE.Expired; message expired in unreachable destination queue. Reason: The mailbox recipient does not have a mailbox database ## I have searched through my whole directory and cannot find 'infrastructure' anywhere. Also, when I try and create an alias in Exchange using infrastructure, it automatically makes it infrastructure2. An alias exists on our POP3 server which should be used just like the rest of them, but for some reason Exchange is seeing infrastructure@mydomain.com as an address somwhere and is not sending it. Any ideas? Regards, Terry Terry http://www.sucked-in.com

i had same issueRestart the transport service on the 2007 server MCSE,CCNA,VCP,APP

Hi, I have rebooted the server to undergo maintenance and this issue has still appeared. I have also restarted the Transport service and no e-mail gets sent. It doesn't even get received by the send connector smtp server so for some reason it is staying in the Exchange queue and not sending. Any other ideas?Terry http://www.sucked-in.com

Turns out by running the New-MailContact command at the Shell I received this error: New-MailContact : The proxy address "SMTP:infrastructure@domain.com" is already being used by "domain.local/Microsoft Exchange System Objects/Infrastructure". Please choose another proxy address. At line:1 char:16 I went into that folder and sure enough there was an orphaned object there, appeared to be a Public folder of that name at some point except it wouldn't show up in the Public Folder management console. I deleted it and now mail is flowing correctly. You don't see this error from the Management Console as it automatically appends a 2 onto the address when you try and create it, which is a bit silly I would think. So.. problem solved! Terry http://www.sucked-in.com