?
Solved

Ramdom NDRs -    There was a SMTP communication problem with the recipient's email server.

Posted on 2008-06-13
6
Medium Priority
?
1,443 Views
Last Modified: 2013-11-30
For  while now, different users around the office are ramdomly receiving bounce backs when sending emails through their Outlook 2003 client / Exchange 2003, with the error being;;

   There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.


When I check eventvwer on exchange server I find this error;


A non-delivery report with a status code of 5.5.0 was generated for recipient rfc822;acct.??@???.????.com (Message-ID <242749538A520140A585FCF03D46FCB10104F86C@??????-srv01.unsworthcl.com>).  
Cause:  This message indicates a generic protocol error (SMTP error).  For example, the remote SMTP responds to an issued EHLO with a 500 level error and the sending system will QUIT the connection and report this with NDR indicating the remote SMTP server cant handle the protocol.    
Solution:  View the SMTP log or run a netmon trace to see why the remote SMTP server rejects the protocol request.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.


I have run SMTP Diagnostics at mxtoolbox.com

RESULT: smtp1.unsworthcl.com
Banner: SMTP ESMTP [156 ms]  
Connect Time: 3.062 seconds - Good
Transaction Time: 3.812 seconds - Good
Relay Check: OK - This server is not an open relay.
Rev DNS Check: OK - 83.104.227.178 resolves to uglog2-adsl.demon.co.uk
GeoCode Info: Geocoding server is unavailable
Session Transcript: HELO please-read-policy.mxtoolbox.com
250 SMTP [141 ms]
MAIL FROM: <test@mxtoolbox.com>
250 ok [156 ms]
RCPT TO: <test@mxtoolbox.com>
553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1) [141 ms]
QUIT
221 SMTP [156 ms]
 

RESULT: smtp2.unsworthcl.com
Banner: SMTP ESMTP [250 ms]  
Connect Time: 0.344 seconds - Good
Transaction Time: 8.375 seconds - Not good!
Relay Check: OK - This server is not an open relay.
Rev DNS Check: OK - 80.177.32.174 resolves to mailgate.unsworthcl.com
GeoCode Info: Geocoding server is unavailable
Session Transcript: HELO please-read-policy.mxtoolbox.com
250 SMTP [3375 ms]
MAIL FROM: <test@mxtoolbox.com>
250 ok [359 ms]
RCPT TO: <test@mxtoolbox.com>
553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1) [3766 ms]
QUIT
221 SMTP [281 ms]
 


I cannot identify problem, please help.
0
Comment
Question by:uklogistics
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
6 Comments
 
LVL 19

Accepted Solution

by:
bevhost earned 600 total points
ID: 21777982
It would be nice to know what the actual 500 error message text was.
Is that in the bounce back message?

It could be that your PTR records aren't setup quite right.
The PTR record should have a matching A record that points back to the same IP address and this should match the EHLO name or FQDN of the exchange server.

If you have multiple mail servers NAT behind one firewall create multiple PTR records for the same IP.

Many exchange servers announce themselves as servername.mydomain.local which cannot be found in the DNS.

To check this in your exchange go into Exchange System Manager
Expand Servers->SERVERNAME->Protocols->SMTP->Default
Right Click then Properties
Delivery TAB
Advanced Button
change the fully qualified domain name to match your DNS entries.

See section 2.1 or RFC1912.
0
 

Author Comment

by:uklogistics
ID: 21779294

No the error doesn't appear in the bounce back, and i'm not too sure why; Is there any way I can check?


Your message did not reach some or all of the intended recipients.

      Subject:      FW: ?????????????
      Sent:      13/06/2008 10:50

The following recipient(s) could not be reached:

      '??.??@???.???.com' on 13/06/2008 10:50
            There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.
            <unsworthcl.com #5.5.0>

It appears the Fully Qualified Domain name is already present , and appears correct : unsworthcl.com
see screen shot

http://img71.imageshack.us/img71/7886/smtpserverpropertiesgk0.jpg
0
 
LVL 13

Assisted Solution

by:cshepfam
cshepfam earned 150 total points
ID: 21779573
You may be under an NDR attack:


http://support.microsoft.com/kb/886208
0
What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

 
LVL 19

Assisted Solution

by:bevhost
bevhost earned 600 total points
ID: 21782984
You could try relaying your outbound mail through a smart host which will always accept your mail and perhaps has better logging and or more understandable bounce messages.
If you want a free windows bases SMTP server see http://www.hmailserver.com/
0
 

Author Comment

by:uklogistics
ID: 21830205
Hi
My ISP is Demon, and we smarthost to post.demon.co.uk as shown in attachment . From what I understand, Demon smarthost are just providing a generic smtp error :  #5.5.0 . I'm i correct?

If that is the case, can anyone recommend another smarthost I could use, as suggested by bevhost, who might be more reliable and provide understandable bounce errors?

thanks


smarthost.gif
0
 

Author Comment

by:uklogistics
ID: 21878708
I have identied a common pattern . These NDRs appear to occur at peak times of the day, when larger than usual emails are in/out . Could this be related to the number of concurrent connections my smarthost (post.demon.co.uk) will allow at any one time. Is there anyway I can do to exchange to test that this is the case?
0

Featured Post

Has Powershell sent you back into the Stone Age?

If managing Active Directory using Windows Powershell® is making you feel like you stepped back in time, you are not alone.  For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

How to resolve IMCEAEX NDRs in Exchange or Exchange Online related to invalid X500 addresses.
If you troubleshoot Outlook for clients, you may want to know a bit more about the OST file before doing your next job. IMAP can cause a lot of drama if removed in the accounts without backing up.
how to add IIS SMTP to handle application/Scanner relays into office 365.
Established in 1997, Technology Architects has become one of the most reputable technology solutions companies in the country. TA have been providing businesses with cost effective state-of-the-art solutions and unparalleled service that is designed…
Suggested Courses

801 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question