Why most, but not all email makes it to the server?

[jmair]

I've been racking my brain on why most locations are able to send email to us, however other locations (other schools for example) get mail bounced back. The locations that can make it always make it and the ones that don't never do.

 

my exchange server 2010 ip is 64.25.235.35. My domain is parkcountyre2.org. My exchange domain is mail.parkcountyre2.org. I pass the http://www.mxtoolbox.com/ mx record checks and the inbound email flow checks from http://www.testexchangeconnectivity.com . I also pass the Best Practice Analyzer on everything I've tested.

 

I hired a Exchange tech to remote in and confirm that everything is setup correctly.

 

Any suggestions would be greatly appreciated.

[teklogic]

Did you recently or, are you on a County connection. We had all sorts of issues with there redirection, mainly not receiving mail from other schools.

[ConradJones]

would help to post the bounce message.

[mattysmith80]

My bet is that if you are on a local authority connection or a regional broadband type connection they will have something up on the firewall which will be blocking your emails getting to certain sites that are also connected the the authority type connection.

 

From my personal experience we have had this issue for ages. What happens is that your email leaves your site, it leaves the network then hits the Internet, it then enters the network again and sees that the email has come from within a school on the same wan... It then blocks it because the firewall sees the traffic as trying to attack another wan network.

 

I hope this makes sense... Basically a firewall rule needs to be put In place to resolve all mail servers so it resolves in on the wan

 

We also have issues where we host web sites and share point that primary schools you and they can't connect to them as again traffic goes out and back in and gets blocked

[ConradJones]

My bet is that if you are on a local authority connection or a regional broadband type connection they will have something up on the firewall which will be blocking your emails getting to certain sites that are also connected the the authority type connection.

 

From my personal experience we have had this issue for ages. What happens is that your email leaves your site, it leaves the network then hits the Internet, it then enters the network again and sees that the email has come from within a school on the same wan... It then blocks it because the firewall sees the traffic as trying to attack another wan network.

 

I hope this makes sense... Basically a firewall rule needs to be put In place to resolve all mail servers so it resolves in on the wan

 

We also have issues where we host web sites and share point that primary schools you and they can't connect to them as again traffic goes out and back in and gets blocked

 

we've had v similar

[jmair]

would help to post the bounce message.

 

Diagnostic information for administrators:

 

Generating server: SVADSERVER.svad.local

 

[email protected]

#550 4.4.7 QUEUE.Expired; message expired ##

 

Original message headers:

 

Received: from SVADSERVER.svad.local ([::1]) by SVADSERVER.svad.local ([::1])

with mapi; Thu, 2 May 2013 10:17:40 -0600

From: Rich Krumholz

To: Jesse Mair

Date: Thu, 2 May 2013 10:17:38 -0600

Subject: RE: Test Email

Thread-Topic: Test Email

Thread-Index: Ac5HT8wQMiwDWJtXS+2NcJadnw39MAAALynw

Message-ID:

References:

In-Reply-To:

Accept-Language: en-US

Content-Language: en-US

X-MS-Has-Attach:

X-MS-TNEF-Correlator:

acceptlanguage: en-US

Content-Type: multipart/alternative;

boundary="_000_E86E0F5C67E40C4ABCB57C71C575E44D01329A3B963ASVADSERVERs_"

MIME-Version: 1.0

[jmair]

I see the lines:

References:

In-Reply-To:

 

fairplay_2012.parkcounty.int is the FQDN of the server on site.

[ConradJones]

if you end up with some emails its me!

[ConradJones]

Telnet test goes through okay.

[sukh]

sorted? Test a new email from sender org to your org. Check queues on sender's org.

[ConradJones]

no i don't think so, i was just saying a telnet test works goes through fine, and the mail server isn't doing a lookup on the ip address of the sender.

[ConradJones]

Does the same sender always get an NDR or do they sometimes get through and sometimes get bounced?

[sukh]

the ndr just says messages is expired, we don't know why. When the sender emails and message is in the que it will give a reason why. What does that say?

[mattysmith80]

Are the places your sending to on the same WAN ?