Exchange 2003 SBS #4.4.7 NDR TO OUR SERVER

I've got a situation where my client is telling me (and I've seen) a
few domains are unable to send email to us without getting 4.4.7 errors
returned to the sender. I've disabled all incoming mail filters (IMF)
on the exchange server, from the outside world from multiple IP
addresses I can telnet to 25 to the mail server as well as MANY MANY
MANY users are able to send mail to this exchange server, only a few
cannot.

I'm looking for some general guidance on where I can look from here to
figure this out.

I've done the following:
-Disabled SMTP filtering on Exchange
-Disabled SMTP FIltering on PIX
-Routed all SMTP Traffic through our ISP via Virtual Server (there is
no SMTP Connector)
-Checked SMTP logs and found NO CONNECTIONS from these domains
attempting to send mail to us
-Check DNSREPORT for any DNS errors on our DNS Server...

Anything else I can look for?!? Thanks!

~Jeff

.

Relevant Pages

  • [NT] Vulnerability in Exchange Server Allows Remote Code Execution (MS05-021)
    ... A remote code execution vulnerability exists in Microsoft Exchange Server ... their choice in the security context of the SMTP service. ...
    (Securiteam)
  • Re: message in retry state
    ... Ran into this a few times if it was an Exchange Server on the sending side. ... ISP MTU problems were causing the EHLO to drop completely and not fail over ... connector sending all email via HELO instead of EHLO. ... Routing Engine and SMTP service to make it take effect, ...
    (microsoft.public.exchange.admin)
  • Re: Delayed delivery of messages and NDRs following a server reboo
    ... I think its a bug with the SMTP temp tables or something. ... assistance, contact your system administrator. ... recipient's email server in a timely fashion. ... Does your Exchange server deliver email directly to the internet? ...
    (microsoft.public.exchange.admin)
  • Re: Issues sending outside email after internal to 2 servers worki
    ... The exchange server can perform name resolution properly? ... What address space did you enter on the connector to your other mail ... delay in receiving the email on the outside world? ... You can't tell from the SMTP queues ...
    (microsoft.public.exchange.setup)
  • Re: urgent
    ... directory then contact a foreign smtp system if the user is not found. ... 2- Why the exchange server it self, unable to route to the foregin System ... Users able to send to Egypt Office Without any Problems. ... are have the same domain, the messages did not reach for London user, ...
    (microsoft.public.exchange.admin)
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