Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

SMTP Protocol Returned a Permanent Error 503 - Duplicate HELO

Posted on 2004-10-29
5
Medium Priority
?
1,773 Views
Last Modified: 2008-01-09
Hi,

An external sender received the following error when trying to email a legitimate recipient in my domain:  "Error transferring to MAILSERVER.DOMAIN.COM; SMTP Protocol Returned a Permanent Error 503 mailserver.domain.com Duplicate HELO".

Could this be somehow caused by having multiple Exchange servers in the same Exchange org, with MailMarshal as the relay server to the Internet?
0
Comment
Question by:Shepsys
  • 2
  • 2
5 Comments
 
LVL 5

Expert Comment

by:Maharajkp
ID: 12449787
I guess MX is pointing to "MailMarshal" ... and is receiving and forwards emails to Exchange ...
If that's the case and NDR is generated by Exchange ... make sure of Communication between MailMarshal & Exchange

From MailMarshal ... do SMTP Communication Test
Telnet to Port 25 to Test SMTP Communication
http://support.microsoft.com/kb/153119

and try to submit the message
0
 

Author Comment

by:Shepsys
ID: 12463870
Correct.  The MX record is pointing to MailMarshal and is forwarding mail to/receiving mail from the Exchange servers.

Telnet tests work fine. This is the only error I have seen like this.  All other email traffic seems to be routing fine.  Just this one particular sender is having a problem.
0
 
LVL 5

Accepted Solution

by:
Maharajkp earned 1000 total points
ID: 12465827
If that's the problem then I hope you have tried that telnet test ... with his Email Address on "mail from: ..." ... and if that has worked then you can wash your hands ... its not your exchange problem.

you can carry out that same test from your home machine on your MX record ... and see if that "MailMarshal" is rejecting that message or what

0
 

Author Comment

by:Shepsys
ID: 12466789
I have verified that telnetting with the sender's info works fine from outside the domain so, as you suggested, it must not be my exchange problem.

Thank you very much for your input.  Will close with an A.
0
 
LVL 1

Expert Comment

by:ksteirer
ID: 13280216
We had a similar problem while using MS SMTP to send 3-4 email into one of our own email servers from a remote location and got around this by putting a 1 second pause between emails. Apparently the spam filter server we use (external provider) mistakenly saw the multiple email connections as a single connection with multiple HELO attempts.

Since this only began occuring at the precise moment the spam filter was enabled (and is corrected by disabled the spam filter) I look at it as a server problem - the spam filter server. It looks like the mail server software is poorly written or set too sensitively (or could have even been designed that way). After all, who wants multiple connects/disconnects to your server every 1/4 second? - this would be similar to a ping attack. Regardless, the only control the user would have, that I see, would be to put pauses between the emails - if they were using a script.

Would anyone have a better insight on this?
0

Featured Post

Veeam Task Manager for Hyper-V

Task Manager for Hyper-V provides critical information that allows you to monitor Hyper-V performance by displaying real-time views of CPU and memory at the individual VM-level, so you can quickly identify which VMs are using host resources.

Question has a verified solution.

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

Stellar Exchange Toolkit: this 5 in 1 toolkit comes loaded with mega-software tool. Here’s an introduction to tools’ usage and advantages:
If you have come across a situation where you need to find some EDB mailbox recovery techniques, then here you will find the same. In this article, we will take you through three techniques using which you will be able to perform EDB recovery. You …
In this video we show how to create an email address policy in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.:  First we need to log into the Exchange Admin Center. Navigate to the Mail Flow…
The basic steps you have just learned will be implemented in this video. The basic steps are shown to configure an Exchange DAG in a live working Exchange Server Environment and manage the same (Exchange Server 2010 Software is used in a Windows Ser…
Suggested Courses

916 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