Outgoing email fails when sent to external domain accounts. We have a sub office that just requires pop email accounts. No other SBS services. They also need to use our email domain name. The sub office mail is received on the ISP’s mail server. When users at head office working on the SBS server send mail to the sub office, the mail doesn’t leave the SBS LAN. All other outgoing and incoming mail works through the SBS Exchange server to other domains, except in the case if the outgoing emails domain name is ours and the account is only on the ISP’s server. Example. User Fred@ourdomaim.com at head office LAN, sends mail to Tom@ourdomain.com at sub office. Fred gets this error. #550 5.1.1 RESOLVER.ADR.RecipNotFound; not found ## How its setup now. The domain name Mx record points to our ISP’s mail server. The SBS pop3 connector downloads the mail from this server. Internal Exchange LAN mail sends out on the SBS configured Smart Host of our ISP. How can I get the Exchange server to send mail to an account outside our LAN?

So you are sharing the same SMTP namespace between Exchange and whats on the ISP? ( If you are , why not simply host the email on your SBS server instead of the ISPs?) http://technet.microsoft.com/en-us/library/bb676395(EXCHG.80).aspx How to Configure Exchange 2007 to Route Messages for a Shared Address Space

Hi Bdiesel, Any update for your issue? As you refered, you use the same smtp name space as the your suboffice, and because your sub office use third party hosted service, when you send email to the Tom@ourdomain.com, server would resolve it as local mailbox, but actually there is no mailbox for the account, so it failed. Regards! Gavin

I am under the impression that the server tries to deliver the mail on the local domain (which is normal because the sent mail also goes to ourldomain.com) and that the mail address is not known you our domain. If you check your exchange console for the mail address of Tom, does it exist on your server ? Greets, stef