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Exchange 2010 woes

I typed up a real nice question which i just lost thanks to my apple magic mouse scrolling feature. So here is the short and sweet version.

Cant send email to only two domains. Message stops in Exchange queue with this error:  421 4.4.0 Remote server response was not RFC conformant

Google searches have taken me down the DNS path so I took a look via MXToolBox.com. Everything seemed to check out. Also ran Exchange mail flow tools, looks good. I do receive a nice little bounce back with #550 4.4.7 QUEUE.Expired; message expired ## which is just telling me the message timed out in the queue. The recipients say they have not had complaints from anyone else, just me.

Thanks in advance for any help you can provide. This has been an on going issue and I am about to wrap some blue cat 5 around my neck and jump.
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Decker_1
Asked:
Decker_1
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1 Solution
 
Decker_1Author Commented:
Follow up with some info you may need to help.

Domains I can not send to: mednet-tech.com & roseandassociates.com

My domain: marioneye.com

My mail server: mail.marioneye.com
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TI2HeavenCommented:
Could you give us a log of your send connetion when is trying to connect to those 2 domains?
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HonezCommented:
I havent seen an error like this before.  Your DNS looks good, what type of firewall are you using?
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Todd GerbertIT ConsultantCommented:
I would also be curious as to what firewalls/filtering those two domains are using. At first glance it seems they're both using Barracuda's - I'm not particularly familiar with those devices, but I wonder if they're flagging you as SPAM and the response they generate in that case intentionally doesn't conform to RFC specs?
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HonezCommented:
My curiosity is if the users firewall was a PIX or ASA.  If so he may need to disable the inspect SMTP, or FIXUP SMTP pending on which version that is being used.
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Decker_1Author Commented:
I am using a watchguard firewall. Not sure what they are using. I also have a barracuda but it only filters incoming mail. I can provide the requested logs in awhile.
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HonezCommented:
I dont have alot of experience with the watchguard, but from what I understand it can have similar problems to the PIX.  

Look at this article:

http://support.microsoft.com/kb/320027

Attempt to telnet to the affected email servers over port 25 and see what the reponse is.

telnet mail.mednet-tech.com 25
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WORKS2011Austin Tech CompanyCommented:
you could configure a smart host and test, if the problem persists you definitely know it's on the receiving end, if not and I expect it won't are you open to using a smarthost?

there may be something incorrectly resolving with your ISP DNS records, have you checked these? Does you ISP have reverse DNS configured?

this link shows you how to configure a smarthost
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Exchange_GeekCommented:
These boxes have genuine problem

here is what MXtoolbox has to state for each of its MX Records

ns1.mednet-tech.com

9/1/2012 4:05:35 PM Connection attempt #1 - Cannot access a disposed object.

ns2.mednet-tech.com - works good.

EHLO please-read-policy.mxtoolbox.com
250-web1.mednet-tech.com
250-AUTH=LOGIN CRAM-MD5 PLAIN
250-AUTH LOGIN CRAM-MD5 PLAIN
250-STARTTLS
250-PIPELINING
250 8BITMIME [62 ms]
MAIL FROM: <supertool@mxtoolbox.com>
250 ok [47 ms]
RCPT TO: <test@example.com>
553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1) [47 ms]
QUIT
221 web1.mednet-tech.com [47 ms]

ns3.mednet-tech.com

9/1/2012 4:08:56 PM Connection attempt #1 - Timeout occurred due to inactivity. [16.22 sec]

Now to test the other mail domain.

Regards,
Exchange_Geek
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Exchange_GeekCommented:
both these domains have same Name Servers, however their MX Records are resolving fine.

Work with telnet from your server to their MX Records and see if you can get responses.

Next, create two send connector with each address added to respective connector and their MX Records added as smart host. Restart Transport services and provide feedback.

Regards,
Exchange_Geek
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Decker_1Author Commented:
It seems that i can telnet into mednet-tech.com. Output below

220 barra01.mednet-tech.com.mednet-tech.com ESMTP (7080e2d326806e41b58bd5807a4d8
ef6)
help
214-Usage: HELP <topic>
214-Topics:
214-    HELO EHLO MAIL RCPT DATA
214-    VRFY EXPN RSET NOOP QUIT
214 End of HELP info
┬┐
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Decker_1Author Commented:
Tried creating new send connectors with smart hosts. Same error in the exchange queue. : 421 4.4.0 Remote server response was not RFC conformant

Only difference is I receive that error MUCH faster with the send connectors added in.
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Todd GerbertIT ConsultantCommented:
Try using telnet to connect to the mail servers in question to actually deliver a piece of mail to a valid recpient address, and post the remote server's response here. You can also try telnetting to your Exchange server and attempting the same thing (depending on your particular installation, that might not work though).

Entries in Bold are what you type, replace Italicized entries with valid values; note that parentheses and angle-brackets should be included; you can't backspace, so make sure you type lines correctly the first time, or copy/paste from Notepad. Make sure you're telnetting from your Exchange server, otherwise this isn't really useful as a diagnostic step.

220 barra01.mednet-tech.com.mednet-tech.com ESMTP (7080e2d326806e41b58bd5807a4d8ef6)
HELO your_domain.com
250 barra01.mednet-tech.com.mednet-tech.com Hello your_mail_server.your_domain.com [192.168.227.249], pleased to meet you
MAIL FROM:<your_address@your_domain.com>
250 Ok
RCPT TO:<recipient_address@mednet-tech.com>
250 Ok
DATA
354 Start mail input; end with <CRLF>.<CRLF>
Content-Type: text/plain
Subject: Test Message
To: "Recipient Name" (recipient_address@mednet-tech.com)
From: "Your Name" (your_address@your_domain.com)

Test message delivered by hand directly to SMTP server at mailm.mednet-tech.com; please disregard.
.

250 Ok: queued as ABCDEF123456
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Decker_1Author Commented:
First result:
220 barra01.mednet-tech.com.mednet-tech.com ESMTP (7080e2d326806e41b58bd5807a4d8
ef6)
helo marioneye.com
250 barra01.mednet-tech.com.mednet-tech.com Hello marioneye.com [64.83.255.82],
pleased to meet you
mail from: rdecker@marioneye.com
250 Ok
rcpt to: coordinators@mednet-tech.com
550 Blockedcv


Connection to host lost.



Second result:

220 barra01.mednet-tech.com.mednet-tech.com ESMTP (7080e2d326806e41b58bd5807a4d8
ef6)
helo marioneye.com
250 barra01.mednet-tech.com.mednet-tech.com Hello marioneye.com [64.83.255.82],
pleased to meet you
mail from: rdecker@marioneye.com
250 Ok
rcpt to: arose@roseandassociates.com
550 Blockedp@
RCPT TO: arose@roseandassociates.com
550 Blockedpo

500 Syntax error, command unrecognized

500 Syntax error, command unrecognized

500 Syntax error, command unrecognized


Connection to host lost.

C:\Users\Administrator>


Something is skewed here, I find it strange that when i type "telnet mail.roseandassociates.com 25" the server responds - barra01.mednet-tech.com.mednet-tech.com
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Todd GerbertIT ConsultantCommented:
Both those domains are using the same mail server (presumably they're two different names for the same company, or one company owns the other, etc).

The server response you're seeing suggests to me that they're Barracuda is rejecting mail from you. Either it's decided you're a spammer, or YOUR server is on a block-list (try using mxtoolbox.com to check your own mail server).

Either way, you will probably need to work with the remote system's administrator to resolve your problem.
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Decker_1Author Commented:
I read an article a little while ago when this problem started about Exchange 2010 having this issue when sending to hosted e-mail accounts from Office 365. I cant seem to find the article now, but has anyone ever heard of this before?
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Todd GerbertIT ConsultantCommented:
I don't think that applies here, their server is definitely issuing a "Blocked" status in response to your attempt to deliver mail.

Did you check mxtoolbox, or contact the remote admin yet?
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Decker_1Author Commented:
Contacted the remote admin. Problem seems to be solved. I will continue to test and report back this afternoon.

Side note: the one company uses the other to host their mail, small world huh.
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Decker_1Author Commented:
The problem was on the med net tech side. We were working with them on a new website and they just assumed we would be using them to host our mail, which we are not. Their admin wouldn't tell me what he did to fix it, just that it was fixed.<br /><br />Thanks to everyone that provided help!!
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