On 3/22/08 6:53 PM, "Eric Shubert" <[EMAIL PROTECTED]> wrote:
> Micah Abrams wrote:
>>
>>
>> On 3/22/08 9:41 AM, "Eric Shubert" <[EMAIL PROTECTED]> wrote:
>>
>>> Micah Abrams wrote:
>>>>
>>>> On 3/22/08 8:24 AM, "Eric Shubert" <[EMAIL PROTECTED]> wrote:
>>>>
>>>>> Micah Abrams wrote:
>>>>>> List -
>>>>>>
>>>>>> I have been getting sporadic reports from users that people attempting
>>>>>> to send them msgs are receiving a bounce with following error:
>>>>>>
>>>>>> 511 sorry, no mailbox here by
>>>>>> that name (#5.1.1 - chkuser)>
>>>>>>
>>>>>> The users identified in the bounce msg definitely exist on the server
>>>>>> (no mis-spellings etc..) and these users are receiving mail otherwise.
>>>>>> I have checked the smtp logs and they report Œfound existing recipient¹
>>>>>> when the msg arrives. This particular server is also very low volume.
>>>>>> Any help/ideas would be much appreciated. This is a new install using
>>>>>> qmail-toaster-1.03-1.3.15.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Micah
>>>>> Does the send log give a clue?
>>>> Thanks for the quick response. Unfortunately, there is nothing in the send
>>>> log for these msgs at that time... Also, on this particular msg (although
>>>> I
>>>> don't think its always the case) the original sender sent the msg to 3
>>>> recipients on this server one of which was really did not exist. However
>>>> the bounce says that all 3 users do not exist (separate chkuser line in the
>>>> bounce for each user).
>>>>
>>>> Micah
>>>>
>>> I think you just explained what's happening.
>>>
>>> Mail servers handle multiple recipients to the same domain in different
>>> ways. For instance, qmail sends each message separately, which ensures that
>>> deliverable copies are delivered, at the expense of bandwidth. Some other
>>> servers (I don't know which ones off hand), in order to preserve bandwidth,
>>> send a single copy to all recipients in the same domain. When such a message
>>> arrives qmail splits it out to each recipient, but only after the message
>>> has been accepted (qmail cannot split it out beforehand). Since there's an
>>> invalid address in the message, qmail cannot receive it, and must bounce the
>>> entire message. It wouldn't be possible to deliver the valid ones and bounce
>>> just the invalid ones. That's why qmail does things the way it does - 1
>>> recipient per message. When a mail server sends a message with multiple
>>> recipients, this is what happens. It's 'normal' (albeit undesirable)
>>> behavior of some mail servers. In addition, it's practically impossible for
>>> the user to distinguish which address was invalid in this scenario.
>>>
>>> Any way to find out which MTA the sending server is running? (just curious)
>>>
>>> HTH
>>
>>
>> Thanks again for your timely and informative response. It goes a long way
>> in helping to diagnose the problem. I am not 100% sure about the sending
>> server, but I believe its some version exchange or at least running on
>> windows. Do you happen to know if this would be the expected behavior of an
>> exchange smtp server?
>>
>> Thanks,
>>
>> Micah
>>
>
> Not off hand. Some diligent googling might give you an answer. If you come
> up with one, please let us know.
I didn't have much luck on google so I setup an exchange account and tried
it out. I sent a msg with one valid and one invalid recipient to my
qmail-toaster and sure enough it generated a bounce for both addresses with
the chkuser 511 error msg.
Thanks again for all the help -
Micah
---------------------------------------------------------------------
QmailToaster hosted by: VR Hosted <http://www.vr.org>
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
