Can't send mail without Smart Host

[ehartle]

Hey all,
I've got EX2K running on win2K Server. My connection to internet is adsl. I host my own dns. Mail comes and goes just fine but only if I specify to forward mail to a Smart host (my ISP's smtp Server). If I specify to "use dns to route mail", mail will just sit in outbound queues until eventually I get an NDR (but it will send mail to addresses on my isp's domain - mindspring.com). I am no EXchange expert by any means but I have set up dozens of Exchange servers for clients and this is just something that normally works without any special config and I guess I'm wondering if anybody has seen this before or has any idea what might be causing it.
TIA,
Earle

 

[ACraib]

I would guess the problem lies with your DNS and not Exchange. Have you got forwarders set up on your DNS pointing to your ISPs? Can you surf the web from your Exchange server?

 

[ehartle]

Well, I can surf the web from the Exchange server, however forwarders are not enabled. This is a one-server environment so everything runs on this server. I've done a little experimentation and come up with some more interesting bits.... If I dialup to internet via a modem, It will route mail correctly using dns, only when connected to adsl will it not work correctly. Looks like it is something funky going on at the ISP. hmmmm...

earle

 

[VOIPeng]

What DNS entries do you have on the server, the dialup ISP DNS or the DSL ISP DNS entries? Use nslookup to verify that DNS is working because it is most likely a DNS issue, unless your ISP is filtering traffic, which should not be happening. Thank you,
Frank Mirecki