Re: Resolving External MTA MX Records Incorrectly

Tech Tip: Click here to run a free scan for Windows Errors and optimize PC performance

Here are a couple of the Bounces.

Your message did not reach some or all of the intended recipients.
Subject: RE: Request for information on PCI DSS status
Sent: 7/18/2007 12:03 PM
The following recipient(s) cannot be reached:
[user1]@[CompanyName].com on 7/18/2007 12:04 PM
You do not have permission to send to this recipient. For
assistance, contact your system administrator.
<[Our Smtp MTA Name] #5.7.1 smtp;550 5.7.1
<[user1]@[CompanyName].com>... Relaying denied>
[user2]@[CompanyName].com on 7/18/2007 12:04 PM
You do not have permission to send to this recipient. For
assistance, contact your system administrator.
<[Our Smtp MTA Name] #5.7.1 smtp;550 5.7.1
<[user2]@[CompanyName].com>... Relaying denied>

Thanks

--
ExchangeFTW
Exchange Messaging Engineer


"John Oliver, Jr. [MVP]" wrote:

Can you post the NDR?

--
John Oliver, Jr
MCSE, MCT, CCNA
Exchange MVP 2007
Microsoft Certified Partner


"ExchangeFTW" <ExchangeFTW@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:34B4CB1A-2D3D-4948-B261-1998C885ED64@xxxxxxxxxxxxxxxx
We don't use a Smarthost entry in our SMTP Connector. We just have our
Front-End Server resolving the IP addresses and sending the e-mail
directly
to the Company's E-mail server via the internet.

We wouldn't use a Third Party Smarthost such as an ISP's to send e-mail
because we fundamentally try to avoid passing company information over any
3rd party environment.

Any other suggestion on how to resolve the problem of resolving MX records
incorrectly?
--
ExchangeFTW
Exchange Messaging Engineer


"John Oliver, Jr. [MVP]" wrote:

Are you using a Smarthost such as your ISP in your SMTP connector? I am
seeing more ISP's such as AOL, Hotmail, etc. blocking IP addresses from
smaller IP blocks such as DSL circuits. This is usually resolved by
using a
Smarthost entry in your SMTP connector. Typically its your ISP's mail
servers or third party such as filtering services.

--
John Oliver, Jr
MCSE, MCT, CCNA
Exchange MVP 2007
Microsoft Certified Partner


"ExchangeFTW" <ExchangeFTW@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:647543BE-6ADC-4F62-9CA8-3395F760A1B5@xxxxxxxxxxxxxxxx
Occasionally users in our Environment will receive NDRs when they send
an
e-mail to someone they correspond with regularly.

When I check the SMTP Logs to see why this is happening I'm finding
connection denied responses.

I then do an NSLookup
set type=mx
[External Company Domain]
Then get a list of the Company's MX records.

Once I find they IP of their e-mail MXs and compare that to the IP of
the
Connection Denied entry in the SMTP Log they aren't the same as the IP
of
the
external e-mail MX IPs.

Usually it is the IP they have for their Reverse DNS Entry.
This is happening on a Win2k3 SP2 - E2k3 Sp2 Front-end Server.
This server uses a Win2k3 SP2 DC with DNS on it to resolve External DNS
Requests.

Do you have any idea why this happens and what I can do to keep the
issue
from happening?

Thanks

--
ExchangeFTW
Exchange Messaging Engineer


.

Relevant Pages

  • Re: Route to Wildcard SMTP Addresses
    ... I've registered the script on the Front-End Routing Server and the Back-End ... Mailbox Server and it isn't working while on either of them. ... Anti-virus Event Sinks that are registerd, could they be causing a problem. ... Exchange Messaging Engineer ...
    (microsoft.public.exchange.admin)
  • Re: Resolving External MTA MX Records Incorrectly
    ... This looks like the receiving servers are blocking your domain or your IP range. ... > Any other suggestion on how to resolve the problem of resolving MX> records ... > Exchange Messaging Engineer ... >> Are you using a Smarthost such as your ISP in your SMTP connector? ...
    (microsoft.public.exchange.connectivity)