[Mailman-Users] Uncaught bounce notifications

Mark Sapiro msapiro at value.net
Thu Dec 1 18:25:23 CET 2005

Darren G Pifer wrote:
>     I have seen on this mailing list a few posts on the thread of
>"Uncaught bounce notifications" but have not found the answer I need.
>One of our user's received one of these notifications and the list owner
>wants to know why the user received it. She believed that if 
>"Should Mailman send you, the list owner, any bounce messages that
>failed to be detected by the bounce processor?" is set to Yes in the
>Bounce Processing Section, the list owner should only get the bounces
>and not the sender.

This is correct.

>If my understanding is correct, and please tell me
>if I am wrong, sendmail (our MTA) will send a bounce notification to the
>sender regardless of this mailman setting?

What is the sender (original poster) receiving, and why do you think it
is coming from your sendmail and not, for example, the bouncing
recipient's MTA?

When Mailman receives a bounce at listname-bounces at ... and the bounce
is 'unrecognized' and listname's
bounce_unrecognized_goes_to_list_owner attribute is set to Yes,
Mailman will send an "Uncaught bounce notification" to the owner(s)
(but not the moderator(s)) of the listname list. This is the only way
Mailman sends an "Uncaught bounce notification", and the only
addresses it is sent to.

This message has specific charastics as follows:

It is From: sitelist-bounces at grizz.org
    'sitelist' is normally 'mailman'

It is To: listname-owner at ...

It has Subject: Uncaught bounce notification

It is multipart/mixed with the text/plain body -
 The attached message was received as a bounce, but either the bounce
 format was not recognized, or no member addresses could be extracted
 from it.  This mailing list has been configured to send all
 unrecognized bounce messages to the list administrator(s).

 For more information see:

It has a message/rfc822 attachment which contains the unrecognized
bounce message as received by Mailman.

If a user other than an owner of the list received such a message, it
was most likely relayed to that user outside of Mailman. You need to
analyze the Received: headers and other information in the message
received by the unintended recipient to see how it got there.

Note that is is not at all unusual for users to receive _other_ bounce
messages. There are apparently many non-compliant MTAs in use that
will return a bounced post to the poster rather than to the
listname-bounces address, but these messages will not have the
charastics of an "Uncaught bounce notification".

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

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