Exchange not sending smtp out, Unable to bind to dns error   

Hello,
I have a SBS 2000 machine w/ ISA installed. I am unable to send out of
domain email, it will go to the messages with unreacheable destination
queue. I have turned up all error logging to maximum. I am able to
recieve inbound emails fine most of the time, and i am able to telnet
into the server i am trying to send mail to and send manually from
there.

I get the following events in my system log when an attempt is made to
send mail.

Eventid:4000
Source: Msexchangetransport
Message delivery to remote domain 'mail.optonline.net' failed for the
following reason: Unable to bind to the destination server in DNS.

Eventid:984
Source: Msexchangetransport
SMTP GetNextHop returned hr=0x0 in 0 ms.
DestAddr=<text>, Type=<SMTP>
MsgType=0x26, NextHopType=CURRENTLY_UNREACHABLE
Type=<>, Class=<>, SchedId=0xffffff
RouteAddr=<>
Connector=<DNS>

Eventid:974
Source: Msexchangetransport
On master side, the follwoing connector's linkstate is down.

Eventid:975
Source: Msexchangetransport
On slave side, the follwoing connector's linkstate is down.

I am pretty sure this is not due to isa or the firewall since i am able
to telnet into smpt servers and manually send mail.

Any ideas what could be causing this?

date: 1 Dec 2005 14:52:59 -0800   author:   Eric

RE: Exchange not sending smtp out, Unable to bind to dns error   

Hi,

Sounds like the Exchange server cant resolve the external DNS. Try and 
resolve some external domain names from the command line. The standard rules 
on ISA should allow DNS resolution out but it is worth checking.



"Eric" wrote:

> Hello,
> I have a SBS 2000 machine w/ ISA installed. I am unable to send out of
> domain email, it will go to the messages with unreacheable destination
> queue. I have turned up all error logging to maximum. I am able to
> recieve inbound emails fine most of the time, and i am able to telnet
> into the server i am trying to send mail to and send manually from
> there.
> 
> I get the following events in my system log when an attempt is made to
> send mail.
> 
> Eventid:4000
> Source: Msexchangetransport
> Message delivery to remote domain 'mail.optonline.net' failed for the
> following reason: Unable to bind to the destination server in DNS.
> 
> Eventid:984
> Source: Msexchangetransport
> SMTP GetNextHop returned hr=0x0 in 0 ms.
> DestAddr=<text>, Type=<SMTP>
> MsgType=0x26, NextHopType=CURRENTLY_UNREACHABLE
> Type=<>, Class=<>, SchedId=0xffffff
> RouteAddr=<>
> Connector=<DNS>
> 
> Eventid:974
> Source: Msexchangetransport
> On master side, the follwoing connector's linkstate is down.
> 
> Eventid:975
> Source: Msexchangetransport
> On slave side, the follwoing connector's linkstate is down.
> 
> I am pretty sure this is not due to isa or the firewall since i am able
> to telnet into smpt servers and manually send mail.
> 
> Any ideas what could be causing this?
> 
>

date: Fri, 2 Dec 2005 12:01:01 -0800   author:   Darrel

Re: Exchange not sending smtp out, Unable to bind to dns error   

Hi, Thanks for hte response
We were able to resolve external DNS as I was able to telnet into other
smtp servers from that machine and manually send mail from them.

We got this working again by reinstalling exchange(used repair option
in setup) and reapply the service pack. We then reconfigured the server
using the internet connetion wizard and mail started flowing out again.

date: 4 Dec 2005 10:19:26 -0800   author:   Eric