Hi All: We have a domain 'abc.com' hosted on Linux Sendmail System. We are trying migrate some of the users from the Linux System on to an Exchange 2003 Server. The users which will be migrated will use the same Outgoing Domain i.e. 'abc.com'. The mail from the Internet will first hit the MX Server (In this case the Linux Server) which will be then forwarded to the Exchange Server using an IP Forwarding. We have configured the users on the Exchange Server with same SMTP domain as 'abc.com'. The mail flow from Linux to Exchange Servers is working fine. However whenever we trying to send a mail from Exchange Server to the users on the Linux Servers using the same domain name 'abc.com' it throws an error the 'User does not exists in the Organization'. We have already created an SMTP Connector on Exchange Server for the address space 'abc.com' and using Linux server IP as the Smart Host. However this doesn't work. Can anybody help us on the same or the finesse of SMTP Connector. Thanks MZ -- **************** CAUTION - Disclaimer ***************** This e-mail contains PRIVILEGED AND CONFIDENTIAL INFORMATION intended solely for the use of the addressee(s). If you are not the intended recipient, please notify the sender by e-mail and delete the original message. Further, you are not to copy, disclose, or distribute this e-mail or its contents to any other person and any such actions are unlawful. This e-mail may contain viruses. NetMagic Solutions Pvt. Ltd. has taken every reasonable precaution to minimize this risk, but is not liable for any damage you may sustain as a result of any virus in this e-mail. You should carry out your own virus checks before opening the e-mail or attachment. NetMagic Solutions Pvt. Ltd. reserves the right to monitor and review the content of all messages sent to or from this e-mail address. Messages sent to or from this e-mail address may be stored on the NetMagic Solutions Pvt. Ltd.'s e-mail system. ***************** End of Disclaimer *******************