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Gary SzaboFlag for United States of America

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Exchange 2003 Server not delivering to neighboring server on LAN

Howdy all -- apologies in advance for the longish post...I'm trying to be as descriptive as possible.

We have the following components:

1.  SBS 2003 server, running Exchange 2003 (sp2), AD, DNS, file/print.  IP: 192.168.1.11
2. a *NEW* Netgear FVS336G dual-WAN router. LAN IP: 192.168.1.1
3. a Snow Leopard Server (Mac Mini) running Postfix, Apache, etc. All the usual suspects. IP: 192.168.1.12

All was humming along until we installed our new router last weekend, to increase our bandwidth from our split T1 (Logix) to add a new broadband connection (EasyTel).  Our public server IPs are on the T1 side, so we've left this 768Kbps stream purely for server traffic in and out.  Our users go out over the faster broadband 99% of the time as it has less latency.

The problem involves mail delivery from Exchange to Postfix - no.  It just sits in the queue, waiting. Other mail sending directions are as follows:

Mail from Postfix to Exchange - yes
Mail from Internet to Exchange - yes
Mail from Internet to Postfix - yes
Mail from Postfix to Internet - yes
Mail from Exchange to Internet - yes, but with some sites (msn.com, yahoo.com, me.com) there's a bit of volume there waiting too.  Under 30 messages, but still enough to concern me.

Prior to this weekend our ISP (Logix) did our LAN creation stuff (gateway, dhcp,) on their Adtran box, but with the new router all that falls to us now.  We've created new DNS entries on our Exchange box to provide valid IPs to all clients, pointing to the LAN addresses rather than the former WAN ones.

The Netgear dual-WAN router gives us ways to point the traffic from the LAN to whichever WAN interface we require, but I don't see any way to build a point-to-point route so that Exchange will know to send the traffic via the LAN.  My guess is that it's waiting to shoot it out via the WAN, and hence the fat queue.

I've attached a pic of a representative msg via the Exchange Message Tracking.

Thanks in advance,
Gary User generated image
Avatar of Nagarajb
Nagarajb

The mail will not go at all or slowly delivery?. If it is slow delivery check the header of the mail on the recipient side, that will give you an idea where the delay is?

If everything is working fine, then try creating a direct connector to one of the domain and see if the mail is delivered?
Can take a Netmon and check if there is any thing else.
Avatar of Gary Szabo

ASKER

Thanks for your response.

It appears that the mail does not go at all.

Can you be more specific about checking the header?  I assume you're asking me to look at the logs on the Postfix side to see if there's any true delivery attempt?

Your comment about the direct connector brought up another item I forgot to disclose...earlier in the week we modified the main Small Business SMTP Connector to use TLS for authentication briefly, and during that period the mail *did* between these servers.  But it stopped everyone else.

As we have folks sending mail securely to the Postfix server from all over the country, I wonder if there's a way under Postfix to allow everyone external to connect via TLS, but define a trusted server that can send without it.  Any thoughts, anyone?
Well...it appears that the generic Postfix main.cf settings are sufficient to allow any local subnet to send mail to it unencumbered.

It's beginning to look like a Netgear issue.   Perhaps a static routing table entry.
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Gary Szabo
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