451 4.4.0 Primary target IP address responded with 421 4.2.1 Unable to connect Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed
Posted on 2009-04-29
Let me first run over my Exchange 07 setup. I am using an SMTP connector to send email through a 3rd party host "Network Solutions" and for incoming we are using the POP3 connectors. Our domain name is parrishconstruction.com I have set our reverse record to parrishconstruction.com. The reason for routing email through Network Solutions is that when I tried to us Exchange to send and receive email I got a poor sender base and I just seemed like there was more to know then what I did at the time. Network solutions does not support smart host or I would try that, Anyway we keep getting this error on almost every email we send which delays it for some time. It eventually makes it out but it can take as long as a couple hours to get out. Any suggestions? Should I just allow exchange to send and receive email and if so what do I need to make sure is in place to keep your sender rating from falling or becoming black listed, what should our reverse record be it we use exchange? Thanks so much for the help!