On 01/14/2013 02:04 AM, tovis wrote:
>> On 01/11/2013 04:36 PM, tovis wrote:
>>> I'm using exim4 configured with "smart host" on Debian Squeeze.
>>> Also I have fetchmail, courier IMAP and apache2, php5, squirrelmail
>>> combo
>>> for mailing (I have several two booting boxes with win and linux - it
>>> was
>>> the easiest way to have mailing infrastructure for both systems). For
>>> long
>>> time I have no pőropblems, but now I have got several error messages
>>> from
>>> my "smart host":
>>> Header (as it shown in Squirrelmail):
>>> Return-path: <>
>>> Envelope-to: postmaster@???
>>> Delivery-date: Wed, 09 Jan 2013 10:30:40 +0100
>>> Received: from Debian-exim by samu.bubu.dyndns.ws with local (Exim 4.63)
>>> id 1Tsrzc-0001Lv-DR
>>> for postmaster@???; Wed, 09 Jan 2013 10:30:40
>>> +0100
>>> Auto-Submitted: auto-replied
>>> From: Mail Delivery System <Mailer-Daemon@???>
>>> To: postmaster@???
>>> Subject: Message frozen
>>> Message-Id: <E1Tsrzc-0001Lv-DR@???>
>>> Date: Wed, 09 Jan 2013 10:30:40 +0100
>>>
>>> Message (as it shown in Squirrelmail):
>>> Message 1Tsrzb-0001Ls-U7 has been frozen (delivery error message).
>>> The sender is <>.
>>>
>>> The following address(es) have yet to be delivered:
>>> some.one@???: SMTP error from remote mail server after MAIL
>>> FROM:<>
>>> SIZE=2673: host smtp.upcmail.hu [213.46.255.2]: 550 5.1.0 <> sender
>>> rejected
>>>
>>> I think these emails are reading confirmation.
>>> I think, that problem is "Return path" and "sender" fields are empty.
>>> It could be solved by exim4 configuration? It could be the problem of
>>> exim4? I'm not sure :(
>>> Any help?
>>
>> Is smtp.upcmail.hu you, or under your control? Is it your smart-host?
>> It looks like it's trying to deliver an empty-sender mail to "bigfirm.hu".
>>
>> What's the relationship with your "dyndns.ws" address; why did it send
>> this
>> notification there?
>>
>> Can you find out why the empty-sender mail was produced? They're
>> legitimate for
>> Delivery Status Notifications (DSNs), of which one class is a "bounce"
>> (that is, a notification
>> of failure to deliver).
>> Have a look at your logs.
>>
>> It could just be that "bigfirm" are clueless, in rejecting all DSNs.
>>
>> It could, at the same time, be that some spammer faked a "bigfirm" sender
>> address, and you accepted the spam and only later decided you couldn't
>> deliver it, so you generated a bounce. This is legal per the mail
>> protocol
>> standards, but suboptimal in a spam-filled world. If so you need to work
>> harder at spotting and rejecting spam during the SMTP conversation.
>>
>> --
>> Cheers,
>> Jeremy
>>
>>
> Thanks for answer Jeremy!
> smtp.upcmail.hu is my smart host (UCP is my internet provider to).
> I only suspect, that those are "reading confirmation". When sender is
> asking for it, yout open the mail, and send a confirmation - this is
> clalled Delivery Status Notifications (DSNs)?
It's plausible that "reading confirmations" are implemented as DSNs.
> You right, it is only a suspect, because some of my contacts said that
> they would not got confirmation from me. But for years our email addresses
> where used for spam - I've got several times offer for job from myself :)
> I do not know where emails with empty sender are created. I'm use
> squirrelmail as MUA and exim4 as MTA. I do not see how does it work, and
> where sender is became empty (even I do not understand why exim4 is
> transferring these emails, I thought it is restricted by default).
> The first question, could exim4 deliver such an email?
Yes, unless specifically configured to not do so.
Look at the logs.
--
Jeremy
