I have a problem in my exchange 2007 server. The Error is "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..." Is it possible that the cause of this problem is due incorrect ISP reverse DNS pointer? Currently, my DNS setup in DNS forward zone is servername.local and the reverse DNS pointer in ISP is also servername..local. I configured the send connector using the ISP smarthost address which works after several weeks then after that the error repeated again that i cant send emails to other domain. Is split dns can fix this problem?
Please help me how to resolve this problem.
Thank you in advance.