Microsoft Exchange Server 2007 Sending Issue

quik

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Joined
Mar 30, 2004
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1,543
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:

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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Franna

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Apr 18, 2005
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2,126
http://www.themssforum.com/ExchangeSetup/want-MailMarshal/

"On your Exchange 2003 server, can you check the properties of the SMTP
virtual server? Under the "Access" tab and then "Authentication" is
"Integrated Windows Authentication" checked?"

OR

You configured the send connector to send through an exchange server (with
authentication)? Remove authentication from the send connector and you should be fine.
 

quik

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Joined
Mar 30, 2004
Messages
1,543
Thanks for the response guys, found the problem. Your suggestions pointed me in the right direction. You wouldn't believe what it was, I couldn't myself :eek:

This problem has been ongoing for longer than a month, where mail to certain addresses just wouldn't go through. Some of our clients in the UK had become quite upset after our experts and even THEIRS couldn't figure out the problem. They've been running diagnostics/blacklist queries/DNS tools/bla bla for the greater part of 2 months. It obviously started right after we set up the new Exchange 2007 server.

This morning I told them I'd take a look (I'm no exchange expert, it's not even my department). After reading your responses I had a look at the Send Connectors settings (Didn't even know where to find it initially :p) and low and behold, the "experts" used the internal domain name as the FQDN on the send connector. UNBELIEVABLE!!! Two months of drama because of that?? All I could say to a bunch of speachless guys was WTH!!

Occam's razor people, learn it, live it, love it!!! ;)

Our Exchange expert and MCSE couldn't figure this one out, they should actually be fired!! :D
 
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quik

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Mar 30, 2004
Messages
1,543
It would seem that most POP servers don't require or check the FQDN, no wonder people get spammed so much :p
 
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