Exchange 2003 +internal mail not in inboxes, no NDR

Our client is using exchange 2003, installed on a DC with as there FQDN. They are popping their ISP for selected mail with the ISP assigning them as their SMTP and POP servers. Mail sent from the internet is arriving fine. If a user wants to forward it to another user internally using Outlook 2000 client, it never arrives and there is no NDR. In fact I have never seen an NDR. I suspect the emails are arriving in the bad mail folder.


Internal default address is
ISP address is
recipient policy is

How exactly does Exchange 2003 use SMTP to route internal email to outlook clients?

Thank You
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rhettleeConnect With a Mentor Commented:
OK. The reason why they can't recieve their mails when they forward it internally is because they are using their internet profile ( to send it. What happens is that the mails will go to your ISP and never leaves there.

In outlook if you have 2 email accounts in 1 profile after the send button there is another button "account" in which can click and you will have a choice whether to send the email using the Internet mail account or the exchange account.

If you use the exchange account to forward it then the mail would be sent to their exchange server not to your ISP does will be recieve internally. Check your ISP if your domain ( has an email address usually activated to catch all lost emails.

There is no way you can send an email internally by sending it via your ISP's mail server ( since their DNS server will just point it internally and not back to your exchange server.

Anyway hope it clears things.

i'm not sure what you mean by "popping the ISP", the email should automatically be forwarded from the ISP to the Exchange server.  if you are having problems with internal email, it has nothing to do with the isp, all internal email never leaves the exchange server, and since you are receiving external email fine, the isp is working.  

are there any errors in the event log?  
i'm also guessing that this domain is public, ie, not behind a firewall?
what do you mean when you say the ISP address is  if i sent an email to user and user2, where would they go?
Just for confirmation your users have two mailboxes right? 1 on your ISP and the other on your exchange server?

The default address on your exchange is the same as in the (domain) the ISP?
The mails are not arriving on the bad folder mail check your ISP if you have a catch all mailbox activated on them its probably there. Correct me all if im wrong but the mails never leaves your ISP when your user forwards an email using as the SMTP server because your MX record is pointed at your ISP.

If your user is forwarding email what account are they using? Do they have two accounts setup on their outlook(i.e. 1 on exchange and 1 for your ISP?) If thats the case what you could advise them before sending is what account your outlook will use to send the email. Outlook has that option when there is more than 1 email account defined on your outlook profile.

Hope this helps.
mungchimpAuthor Commented:
They are not using exchange for internet email. The Users have POP accounts defined in their local Outlook internet email accounts, (There is no convincing this client to allow exchange to host their email). These pop accounts are using for both SMTP and POP, with the typical setup, works fine. The Question here is that their Internal windows 2003 domain is also as opposed to, local etc. They only use exchange to store their email in the mailbox folders, so there are both Internet email and exchange accounts defined in Outlook.  
   When a user recieves an email, if they want to forward it to another internal user using the Global Address List, it never arrives, no NDR. Also if they compose a new email and send it internally the same result, nothing!

The Exchange default recipient policy has as the primary address, this is why I thought there was perhaps an SMTP/DNS routing issue, both the public and private domain names are the same.
mungchimpAuthor Commented:

I could swear I checked that already and it wouldnt work either way. Ill check today. Goofy thing is they say they never had to choose a sending account and it worked fine up till a week ago. I have a feeling they were forwarding the mail using their ISP's mail. If that was the case then the ISP's address must have been the default reply address.

PS New client. I didnt set up their exchange

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