We have SBS2003 R2 with 3 local users on the server.companyaddress is abc.comlan is abc.localWe have several laptop computers that are used in the field and the mail is retrived directly from our mail host company.We are having problems sending mail from within the "abc.local" domain to joe@abc.com mail address.We get the following message when we try to send email to someone who is part of abc.com, but not on the server...... The e-mail account does not exist at the organization this message was sent to. Check the e-mail address, or contact the recipient directly to find out the correct address. <abc.com #5.1.1>Thanks in advance for any ideas.John

Since you have internal addresses *@abc.com which is not valid for Internet DNS so you need to add a recipient policy for abc.com in your Exchange environment and then you can share same smtp address space with other hosting company.Below article explains you how to configure shared smtp address space and how to set forwarding to hosted company in case email address is not in local exchange server.How to share an SMTP address space in Exchange 2000 Server or in Exchange Server 2003http://support.microsoft.com/kb/321721Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com