[Mailman-Users] Call me Don Quixote... :-(

Mark Sapiro mark at msapiro.net
Sun Nov 15 22:07:20 CET 2009

John wrote:
>I found a detailed bounce in my collection from before I entered a support
>ticket about RBLs at the beginning of Oct.
>I'm afraid I wasn't able to deliver your message to the following addresses.
>This is a permanent error; I've given up. Sorry it didn't work out.
><user at takas.lt>:
> does not like recipient.
>Remote host said: 554 5.7.1 Service unavailable; Client host []
>blocked using dnsbl-1.uceprotect.net; IP is UCEPROTECT-Level 1
>listed. See http://www.uceprotect.net/rblcheck.php?ipr=
>Giving up on
>Maybe I'm just paranoid, but I smell a cover-up... Soon after the support
>ticket, I started receiving the summarized failures and bounces from the smart
>host...  :-/    It's a lot easier to deny an email delivery problem if you
>return a vague bounce message instead of the real thing...

It is possible that the smarthost started using some kind of look-ahead
address verification during incoming SMTP. I.e. they check that the
message is deliverable downstream before accepting it from you and if
it's not, return a generic "554 Message refused."

Note that in the case of the above, they accepted the message from you
and then later sent an email reporting the delivery failure.

In the case of the "554 Message refused." reports you quoted earlier,
they were refusing to accept the message during SMTP from you.

>> How do you authenticate to these servers? Why should they accept and
>> relay your mail?
>hmmm ... 'cause they accept and relay everything else from the server? :-P  (ya
>gotta have some fun when things go wrong or else you'll go nuts. ;-) )

But why? If I attempt to connect to port 25 on the server at, it immediatly closes the connection without sending a
greeting. Why doesn't it do this to you? There are lots of
possibilities, e.g.

- your IP is a known 'good guy' in it's network
- you are connecting to some other port
- you are connecting via SSL with a certificate it recognizes as a
- other possibilities

I ask why, because the answer might have some bearing on the problem
we're trying to understand/solve.

>>>> Does the smtp log say it delivered the post to the appropriate number
>>>> of recipients?
>>> it's hard to say... there is no single entry for the problem list that has the
>>> correct number (446 less a few nomail).
>> What are the recipient numbers in the entry(s) for the message-id of a
>> post?
>If VERP is on won't there only be 1 recipient/message-id, but multiple
>message-ids/post to Non-digest members? I also can't find a match to the
>received message IDs.  It looks like digest is different, 2 entries totaling 262

The individual (non-digest) messages are all the same message with the
original message-id. The message may be delivered to the MTA by the
SMTPDirect.py module in multiple transactions or even (with VERP) in
transactions with a single recipient and a unique envelope sender, but
there is still only one smtp log entry written by Mailman with the
total number of recipients delivered to the MTA.

The message-id in a message received from the list should be logged in
the smtp log.

Two entries per digest with Mailman generated message-ids is correct.
one entry is for the plain format digest and one for the MIME format
digest. These are separate messages with distinct contents, thus two
messages. These may have been delivered to the MTA in multiple
transactions or VERPed, but there are still only one log entry for the
plain digest and one for the MIME digest.

>For now, I'm going to assume (ouch) that it's my provider's problem.  Thanks for
>all for the patience and answers. If nothing else, I learned more about the
>workings of Mailman & qmail.  :-D    I may try shutting off the RFC headers on
>the lists and see if that changes anything...

There is some reason why this only affects one list. The question is
why does the smarthost see mail from this list differently? Does the
smarthost rate-limit you? I.e. does it reject all but the first 300
recipients in an hour or something like that?

Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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