Hi all, I have one client (exch07) which is going to share SMTP address (xyz.com) with another company (exchange 2003) The SMTP sharing space is configured and mail flows are fine from outbound and inbound. If we type the internal email address by mistake between these two companies, such as jim@xyz.com, (it should be cjim@xyz.com ex) We can not receive NDR and I guess due to SMTP sharing space (allows relay) Can anyone help? Thank you.

How are you sharing this space? There are several ways to do it. One way is to give each side its own secondary proxy address (one.xyz.dom and two.xyz.com) and synchronize directories between them so that when you send mail to joe@xyz.com, it sees that he's really joe@two.xyz.com and routes the mail properly to the other Exchange server. It's hard to comment on why you're having problems without more information about how you have configured accepted domains on the Exchange 2007 side and e-mail address policies on the Exchange 2003 side. Also we'd need to know how you've configured mail to route from one organization to the other when the address isn't recognized. -- Ed Crowley MVP "There are seldom good technological solutions to behavioral problems." . "SGryzbowski" wrote in message news:55512239-6760-46ee-805b-92389ca58493... Hi all, I have one client (exch07) which is going to share SMTP address (xyz.com) with another company (exchange 2003) The SMTP sharing space is configured and mail flows are fine from outbound and inbound. If we type the internal email address by mistake between these two companies, such as jim@xyz.com, (it should be cjim@xyz.com ex) We can not receive NDR and I guess due to SMTP sharing space (allows relay) Can anyone help? Thank you. Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."