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  • Status: Solved
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Name resolution for Smarthost FQDN in Exchange 2010 send connector

Hi All

We Journal our email to a 3rd party archive company via SMTP rather than a MAPI mailbiox, we have a journal rule configured to send all email to a specific email address mycompany@3rdparty.com, we then have a send connector configured to send all email for that email address via a smart host which is mailarchive.3rdparty.com

Today everything stopped working and i ended up with 50'000 emails in the queue for this  Smarthost connector.

On troubleshooting i noticed that i could not resolve the FQDN of the smarthost mailarchive.3rdparty.com so thought that must be the issue

However everything kicked back into life and the email queue is going down, heres the twist, even though its now working, from the Hub Transport servers i still cannot resolve mailarchive.3rdparty.com!! so how can this be working??

I turned on verbose logging for the send connector and can see that actually it is making connections to mail.3rdparty.com but i just cant work out how if it cannot resolve the FQDN specified in the send connector how it can possibly get any further.

We have TLS configured for on the send connector and use Basic Authentication over TLS.

Im wondering is there any other way in which this could be resolving

Thanks
0
ncomper
Asked:
ncomper
  • 3
1 Solution
 
Jamie McKillopCommented:
Hello,

If you open the Properties page of your hub transport server and go to the "External DNS Lookups" tab, do you have DNS servers listed here?

-JJ
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ncomperAuthor Commented:
Hi JJ

We dont have any specific DNS servers listed there, we just use the NIC's

We dont have any issues with external name resolution, i can resolve many other external FQDNs sucj as www.google.com etc.

Its just this one in particular

Thanks
0
 
ncomperAuthor Commented:
I got to the bottom of this,

What i thought was the FQDN of a server was in fact a sub-domain, so exchange looks up the MX records for that sub-domain and sends email via one of those.

I did not know you could do this, i have always used either the IP address or FQDN of a relay server as a smarthost target.

Mystery solved.

Thanks
0
 
ncomperAuthor Commented:
Found answer mysel
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