SMTP Connector - queued mail between FE/BE   

I have a medium sized organization with several back-end Exchange servers 
and two front-end servers used as SMTP gateways.  The routing groups are 
setup geographically with two sites being hubs, all the others being 
connected to the hubs.  In each of the hubs is one of the SMTP gateways. 
The back-end servers route mail to each other using routing group 
connectors, and all the sites use one of the two gateways for outbound 
email.  At some point two weeks ago (after Exchange SP2 upgrades and all 
Windows 2003 updates) mail began queuing on the back-end server in one of 
the hubs.  One of the other server admins smarthosted the mail from it to 
the remaining SMTP gateway.  Now, the other servers were updated, and the 
back-end server in the remaining hub is queueing mail in the same manner.

The queue is in the SMTP connector (on the back end server, not the 
front-end), and shows the SMTP connector name followed by what looks like a 
guid.  The mail is stuck there with an error of "Cannot bind to the 
destination server in DNS", but we use AD-DNS and all servers are able to 
locate each other.  If I smarthost the mail from the back-end server to the 
front-end server, mail flows properly.

date: Thu, 8 Jun 2006 16:43:08 -0700   author:   David Sutter alias

Re: SMTP Connector - queued mail between FE/BE   

Hi,

Try to run the winroute program (can be found on the exchange cd) and see if 
the output tells you anything.

Leif

"David Sutter" <ca29086b-2136927634@news.postalias> wrote in message 
news:O21dNV1iGHA.2220@TK2MSFTNGP05.phx.gbl...
>I have a medium sized organization with several back-end Exchange servers 
>and two front-end servers used as SMTP gateways.  The routing groups are 
>setup geographically with two sites being hubs, all the others being 
>connected to the hubs.  In each of the hubs is one of the SMTP gateways. 
>The back-end servers route mail to each other using routing group 
>connectors, and all the sites use one of the two gateways for outbound 
>email.  At some point two weeks ago (after Exchange SP2 upgrades and all 
>Windows 2003 updates) mail began queuing on the back-end server in one of 
>the hubs.  One of the other server admins smarthosted the mail from it to 
>the remaining SMTP gateway.  Now, the other servers were updated, and the 
>back-end server in the remaining hub is queueing mail in the same manner.
>
> The queue is in the SMTP connector (on the back end server, not the 
> front-end), and shows the SMTP connector name followed by what looks like 
> a guid.  The mail is stuck there with an error of "Cannot bind to the 
> destination server in DNS", but we use AD-DNS and all servers are able to 
> locate each other.  If I smarthost the mail from the back-end server to 
> the front-end server, mail flows properly.
>

date: Sat, 10 Jun 2006 14:19:49 +0200   author:   Leif Pedersen [MVP]

Re: SMTP Connector - queued mail between FE/BE   

All of the connectors involved in outbound mail appear to be working (one 
unrelated one isn't).  The only thing that I've identified is that the 
Virtual Server FQDN was changed from the server name to 
mx1.ExternalDomainName.com (what it is aliased as externally).  Could this 
cause a problem when the Back End server tries to send mail to it (after 
correctly identifying it in DNS)?

Also, unrelated, I see a section called "Routing groups not found in Active 
Directory".  Where do they come from and is it worth my time to adsiedit and 
delete them?

"Leif Pedersen [MVP]"  wrote in message 
news:%23HzIugIjGHA.5036@TK2MSFTNGP04.phx.gbl...
> Try to run the winroute program (can be found on the exchange cd) and see 
> if the output tells you anything.

date: Sun, 11 Jun 2006 21:18:16 -0700   author:   David Sutter alias

Re: SMTP Connector - queued mail between FE/BE   

Hi,

I have seen a problem at one client site where they changed the SMTP FQDN to 
the same name as their external name and mail internally stopped because the 
internal server in another routing group were not able to resolve the 
external name to an internal IP address. We fixed the problem at that site 
by adding the MX1 record tho their DNS (fortunately they used a split brain 
DNS).

Leif

"David Sutter" <ca29086b-2136927634@news.postalias> wrote in message 
news:uDedBddjGHA.4776@TK2MSFTNGP05.phx.gbl...
> All of the connectors involved in outbound mail appear to be working (one 
> unrelated one isn't).  The only thing that I've identified is that the 
> Virtual Server FQDN was changed from the server name to 
> mx1.ExternalDomainName.com (what it is aliased as externally).  Could this 
> cause a problem when the Back End server tries to send mail to it (after 
> correctly identifying it in DNS)?
>
> Also, unrelated, I see a section called "Routing groups not found in 
> Active Directory".  Where do they come from and is it worth my time to 
> adsiedit and delete them?
>
> "Leif Pedersen [MVP]"  wrote in message 
> news:%23HzIugIjGHA.5036@TK2MSFTNGP04.phx.gbl...
>> Try to run the winroute program (can be found on the exchange cd) and see 
>> if the output tells you anything.
>
>

date: Mon, 12 Jun 2006 20:16:44 +0200   author:   Leif Pedersen [MVP]

Re: SMTP Connector - queued mail between FE/BE   

This was the problem and solution for me.  After adding in the records in 
DNS mail works perfectly.  No restart of any services required.


"Leif Pedersen [MVP]"  wrote in message 
news:O1cQexkjGHA.4284@TK2MSFTNGP05.phx.gbl...
> Hi,
>
> I have seen a problem at one client site where they changed the SMTP FQDN 
> to the same name as their external name and mail internally stopped 
> because the internal server in another routing group were not able to 
> resolve the external name to an internal IP address. We fixed the problem 
> at that site by adding the MX1 record tho their DNS (fortunately they used 
> a split brain DNS).
>
> Leif

date: Mon, 12 Jun 2006 16:20:21 -0700   author:   David Sutter alias