I had install Microsoft Exchange Server 2003 and it is working fine internally. When i tried to send mail to gmail also it is working . But other than gmail I am unable to sent mail. There is no error message,but messaging is not delivering to the recipient address. There is one error message only when trying to send hotmail. " Your message did not reach some or all of the intended recipients. Subject: test Sent: 11/3/2010 2:58 PM The following recipient(s) could not be reached: bilalmbks@hotmail.com on 11/3/2010 2:58 PM There was a SMTP communication problem with the recipient's email server. Please contact your system administrator. <gscs-exchange.gscsgulf.com #5.5.0 smtp;550 DY-001 Unfortunately, messages from 83.110.6.62 weren't sent. Please contact your Internet service provider. You can tell them that Hotmail does not relay dynamically-assigned IP ranges. You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors.> " But there is no such an error message is appearing when trying to sent mail to yahoo or aol. I can see the mail in sent item,but it is not receiving to the yahoo mailbox. can anybody help one in this issue? thanks in advance, zayed

Easiest solution is to set up a smarthost and then relay through that. In Exchange 2003 that is done on the Virtual SMTP connector or under connectors depending on setup. Other option is to get a static IP to sent from, but using a smarthost often minimizes that risk of being blacklisted. /MartinExchange is a passion not just a collaboration software.