I have a number of list managers with subscribers who are confused as to why their messages are silently disappearing. I've read the archives on how to decipher why a message was shunted, but this is not workable at scale. Is sending an error email back to the sender a consideration?
On 3/2/21 2:52 PM, Pete Ashdown wrote:
I have a number of list managers with subscribers who are confused as to why their messages are silently disappearing. I've read the archives on how to decipher why a message was shunted, but this is not workable at scale. Is sending an error email back to the sender a consideration?
Why are messages being shunted? Each shunted message has thrown some kind of uncaught exception which is logged with a traceback in Mailman's mailman.log.
These should be due to bugs that should get fixed or possibly malformed messages which are almost always spam.
In short, under normal circumstances messages should not be shunted at all and when they are it is something the site admins need to address. It is normally not something the sender of the message can do anything about.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
On 3/2/21 4:09 PM, Mark Sapiro wrote:
On 3/2/21 2:52 PM, Pete Ashdown wrote:
I have a number of list managers with subscribers who are confused as to why their messages are silently disappearing. I've read the archives on how to decipher why a message was shunted, but this is not workable at scale. Is sending an error email back to the sender a consideration? Why are messages being shunted? Each shunted message has thrown some kind of uncaught exception which is logged with a traceback in Mailman's mailman.log.
These should be due to bugs that should get fixed or possibly malformed messages which are almost always spam.
In short, under normal circumstances messages should not be shunted at all and when they are it is something the site admins need to address. It is normally not something the sender of the message can do anything about.
This is good to know. I was concerned that shunting could happen due to HTML or message content (ie: not size).
Pete Ashdown writes:
This is good to know. I was concerned that shunting could happen due to HTML or message content (ie: not size).
We refer to non-distribution due to message content as "filtering" or in the specific case of sending it to the moderation queue as "holding".
*Shunting* is due to a "defective" message, ie, one that Mailman is unable to parse, usually because it does not conform to the email standards. Examples include some spam, deliberate malicious messages, buggy mail clients which put emoji into the subject without encoding them as defined by the MIME standards. Many of these we catch and handle in some way, but by definition non-conforming messages can be anything and if the problem isn't anticipated and they actually cause Python to raise an error, only then the message is shunted.
Things that we intentionally filter on: message size, prohibited content such as executables, number of addressees, and many others are automatically caught and handled by distribution, modification (eg, deleting filtered attachments) and distribution, hold for moderation, rejection (return to sender), or discard (eg, spam).
Anything that is filtered and *not* sent to the subscribers can (at the list owner's option) be set to automatically notify the list owner and/or the sender, with an explanation of why it was held or refused. This is done in the list settings where the filter is enabled.
Steve
participants (3)
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Mark Sapiro -
Pete Ashdown -
Stephen J. Turnbull