Don't know how many of you out there have taken the plunge and started rolling out Exchange 2007, but hopefully one of you can help me.
We have an exchange 2007 which seems to have problems sending to certain destinations. As far as I can tell, sending to most POP destinations works just fine, but when trying to send to certain domains, we get the following error:
We've checked the DNS and reverse DNS records and they all seem correct. The server is behind a firewalled router which forwards traffic on certain ports such as 25,443,3389,etc to the server.
Strange thing is, from another location I can establish a telnet session to one of the destinations without any problems, but from the Exchange server I cannot. We've checked for any blacklistings, which there aren't.
Any help would be appreciated!
We have an exchange 2007 which seems to have problems sending to certain destinations. As far as I can tell, sending to most POP destinations works just fine, but when trying to send to certain domains, we get the following error:
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 to all alternate hosts.
We've checked the DNS and reverse DNS records and they all seem correct. The server is behind a firewalled router which forwards traffic on certain ports such as 25,443,3389,etc to the server.
Strange thing is, from another location I can establish a telnet session to one of the destinations without any problems, but from the Exchange server I cannot. We've checked for any blacklistings, which there aren't.
Any help would be appreciated!
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