I have another thread related to this but I gave up on it. http://www.howtoforge.com/forums/showthread.php?t=31977 I created a web server with OpenSuse 11 using the perfect server setup. All works great running 2 web sites (2 domains) except sending mail to 1 particular domain. The company I set this all up for has 3 web sites 2 I host the 3rd hosted by AMATechtel. E-mail for the 2 domains I host CAN send to anybody EXCEPT the the e-mail of the 3rd domain hosted by AMA. This is the bounce back received: Code: Mar 26 10:20:36 vserver1 postfix/smtpd: connect from hxxx.60.22.xx.static.ip.windstream.net[xx.22.60.xxx] Mar 26 10:20:36 vserver1 postfix/smtpd: NOQUEUE: reject: RCPT from hxxx.60.22.xx.static.ip.windstream.net[xx.22.60.xxx]: 550 5.1.1 <email@example.com>: Recipient address rejected: User unknown in local recipient table; from=<firstname.lastname@example.org> to=<email@example.com> proto=ESMTP helo=<production> I altered code to hide email addy and IP. Nobody else has trouble sending to the 3rd site hosted by AMA only MY server. I contacted them and they report that my server is not on any blacklist of theres and it has to be a problem with my server not them. Checks on MXtoolbox.com report no blacklist. Clients on my server CAN send to ALL except domain hosted by AMA.