Hello, I have a client running Small Business Server 2003. Just the other day, a use started having issues sending email to a specific domain. They get an NDR stating: You do not have permission to send to this recipient. For, assistance, contact your system administrator. <domain.com #5.7.1 smtp;550 5.7.1 user@domain.com: Relay access denied>Any insite on this error would be appreciated.

It says relay acccess denied. It means some device (either your side or the recipient side is blocking you). Chances are high for there side.Try to drop an email through telnet and see if you can. Just ask them if they have some filtering done on there FW or there anti spam device.Raj