Yes I presume so, It says the next domain hop is messagelabs.com and the delivery type is "smarthostconnectordeliver
F
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I have just setup a new Exchange 2007 mail platform. Everything is working fine internal and I have just configured my send connector to route emails out via my smart host (MessageLabs). When I send an external message I can see it in the queue viewer and I can see that its going to the right place but it sits there for about 8 minutes and then finaly does go and I see it in my hotmail/gmail inbox. During those 9 minutes I can see that it keeps retrying every now and then and in the last error field it says the following:
451 4.4.0 DNS Query Failed
Can anyone explain why this is happening. why does it take so long to send the email out and what is wrong with the DNS that is is complaining about.
Your help in this matter would be great.
many thanks
F
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I've seen the same problem before. Firstly, make sure your firewall has an exception for DNS (UDP 53) and SMTP (TCP 25)If you cannot successfully ping the smart host and receive a reponse within a few seconds, I'd suggest clearing the cache of your Internal DNS Server then restarting the DNS Server service on your DC, and restarting Microsoft Exchange Transport Service too.
That should do it.
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by: Chris-DentPosted on 2007-09-19 at 01:49:00ID: 19919033
Which Name is it trying to lookup? Presumably the SmartHost?
Chris