Dear All, I am Mohd Muzaffar, I am not able to send email to a particullar user out side my domain / network. I am getting this error message. There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.<ruh-mail.saudicarrier.com #5.5.0 smtp;550 Denied by policy> But when I send the same mail tomy personal email account ( like Rediff, Yahoo, Gamil ), it goes smoothly without any problem. Can anyone help / or let me know what is issue and how can I resolve it. FYI, We are having 2003 Server, Exchange 2003 & ISA 2004. All this has service pack 2. Many Thanks Muzaffar Ahmed. Network Administrator

I think this is what you are describing: http://support.microsoft.com/kb/895857