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Greylisting Problem

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Rob

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Dec 13, 2005, 6:06:03 PM12/13/05
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I am running Exchange 2003 SP2.
Yesterday, we discovered that one of the organizations that we frequently
email has implemented greylisting on their mail servers.
They told us our messages were not getting through because our mail server
did not understand how to respond to the error codes that the greylist
program was sending back. So, our Exchange server was not properly
re-queueing the messages for a re-delivery.

My question: Does anyone know how I need to change any settings on my
Exchange server so that it will properly re-try so that it will be allowed
through a greylist?

Thanks.

Bobby Janow

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Dec 13, 2005, 10:07:46 PM12/13/05
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I don't believe that there is an actual error message. I thought it's just a
temporary unavailable and then a resend automatically. Exchange is one of
the mailservers that handle greylisting very well. They just resend within
minutes. Possibly your client did not set up the greylist properly. You can
also have them whitelist your domain.

Bj

"Rob" <R...@discussions.microsoft.com> wrote in message
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Rich Matheisen [MVP]

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Dec 13, 2005, 10:24:34 PM12/13/05
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Rob <R...@discussions.microsoft.com> wrote:

>I am running Exchange 2003 SP2.
>Yesterday, we discovered that one of the organizations that we frequently
>email has implemented greylisting on their mail servers.
>They told us our messages were not getting through because our mail server
>did not understand how to respond to the error codes that the greylist
>program was sending back. So, our Exchange server was not properly
>re-queueing the messages for a re-delivery.

The respose should be a 4xx status, indicating a transient, retryable,
error.

What did they tell you was the status they were sending?

What happens to the mail at yur side? Is it requeued? Retried?
Returned as undeliverable?

>My question: Does anyone know how I need to change any settings on my
>Exchange server so that it will properly re-try so that it will be allowed
>through a greylist?

You don't have to do anything. The 4xx status will be retried on the
schedule you set on the SMTP Virtual Server.

--
Rich Matheisen
MCSE+I, Exchange MVP
MS Exchange FAQ at http://www.swinc.com/resource/exch_faq.htm
Don't send mail to this address mailto:h.p...@getronics.com
Or to these, either: mailto:h.p...@pinkroccade.com mailto:melvin.mcp...@getronics.com mailto:melvin.mcp...@pinkroccade.com

Rob

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Dec 14, 2005, 5:41:17 PM12/14/05
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The problem is that we don't get any kind of a response back from the other
mail server. At least, none that I can see.
When I contacted the other mail system admin, he told me that he saw the
initial attempt in his logs. But, I couldn't find anything on my side that
would indicate a retry.
I didn't ask for the specific status that they were sending.

Can I just leave the default values on my SMTP Virtual Server for the retry
to work correctly? Or should I tweak them?

Strange thing....Messages started going through shortly after I wrote this
post. But, the initial message that was sent to that domain never made it
through, and I don't believe an NDR was generated. It just looks like it was
lost.

Thanks.

Rich Matheisen [MVP]

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Dec 14, 2005, 11:01:28 PM12/14/05
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Rob <R...@discussions.microsoft.com> wrote:

>The problem is that we don't get any kind of a response back from the other
>mail server. At least, none that I can see.

Then they aren't greylisting.

>When I contacted the other mail system admin, he told me that he saw the
>initial attempt in his logs. But, I couldn't find anything on my side that
>would indicate a retry.

Do *you* see the conversation in your log? What was the status code
returned in response to your command (probably to the RCPT TO if
they're using the server/from/to triplet to greylist)?

>I didn't ask for the specific status that they were sending.

You shouldn't have to. It should be in your SMTP protocol log.

>Can I just leave the default values on my SMTP Virtual Server for the retry
>to work correctly? Or should I tweak them?

I'd leave 'em alone. You should only have to retry once, and only on
the 1st triplet. After that the messages should be accepted
immediately (well, at least for some period of time).

>Strange thing....Messages started going through shortly after I wrote this
>post. But, the initial message that was sent to that domain never made it
>through, and I don't believe an NDR was generated. It just looks like it was
>lost.

Your SMTP protocol logs would verify that.

Ole Thomsen

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Jan 26, 2006, 9:51:13 AM1/26/06
to
Did you restart SMTP?

I'm facing the same problem after upgrading to Exchange 2003 SP2.

When sending to greylisting sites mail is not resent, and users get no
NDR.

SMTP log shows only the first attempt, mailqueue and mailfolders are
empty.

What's really weird is that after restarting SMTP the previously blocked
emails are resent - and users receive weeks or months old NDRs!?!

I simply cannot figure out where these mails are stored until SMTP is
restarted?

Ole Thomsen

Rich Matheisen [MVP]

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Jan 26, 2006, 8:43:27 PM1/26/06
to
"Ole Thomsen" <o...@networks.dk> wrote:

>Did you restart SMTP?
>
>I'm facing the same problem after upgrading to Exchange 2003 SP2.
>
>When sending to greylisting sites mail is not resent, and users get no
>NDR.
>
>SMTP log shows only the first attempt, mailqueue and mailfolders are
>empty.
>
>What's really weird is that after restarting SMTP the previously blocked
>emails are resent - and users receive weeks or months old NDRs!?!
>
>I simply cannot figure out where these mails are stored until SMTP is
>restarted?

They're in the databases (either .stm or .edb, depending on how they
were sent).

Ole Thomsen

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Jan 27, 2006, 12:35:31 AM1/27/06
to
Rich Matheisen [MVP] wrote:
>>
>> What's really weird is that after restarting SMTP the previously
>> blocked emails are resent - and users receive weeks or months old
>> NDRs!?!
>>
>> I simply cannot figure out where these mails are stored until SMTP is
>> restarted?
>
> They're in the databases (either .stm or .edb, depending on how they
> were sent).

Thanks.

Is there a way to monitor if there's any unsent mail - or will I have to
schedule a restart of SMTP to flush?

Ole Thomsen

Rich Matheisen [MVP]

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Jan 27, 2006, 9:45:36 AM1/27/06
to
"Ole Thomsen" <o...@networks.dk> wrote:

If you're not seeing the messages in the queue viewer then you have a
problem that's different to "unsent mail". You shouldn't have to
restart any services to cause messages to be delivered, or to apear in
the queue viewer.

If you have any 3rd-party application on the server (anti-virus,
anti-spam, etc.) try disabling (or removing) them.

Glasa@discussions.microsoft.com Marcel Glasa

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Mar 6, 2006, 6:25:28 AM3/6/06
to
Hello Ole !

I have probably similar problem.
I have also installing SP2 on Exchange 2003,
but I don't restart anything.

After that, some customers which use graylisting, reports me problems with
mail delivery from our company.

Than, after one month I have dismount Mailboxstore.
After remount, Exchange send lot of old "lost" emails that was unset for
SMTP erros like:
Recipient address rejected: Greylisted
Recipient address rejected: Service temporarily unavailable, please try later
etc.
and Exchange sent also old NDRs.

Ole: have you problems with mail delivery after you restart SMTP ?

mcg.he...@gmail.com

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Aug 5, 2012, 5:09:50 AM8/5/12
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