[Mailman-Users] Mailman version 2.1.9, content filtering action changed??

[Mark Sapiro]

Arthur Hatch wrote:
>
>I need some help with unexplained behaviour changes to the "Content
>Filtering" action of a Mailman list, version 2.1.9. The Mailman list
>is Xxxxxx, and the unexplained behaviour was first noticed with e-mail
>postings on/after Sept.6/07.


And what happened on Sept 6, '07. What changed in your system or your
Mailman.


>The unwelcome changes are that since Sept.6/07, the Content Filtering
>configuration is "not" stripping any e-mail message attachments; even
>though "multipart" and "image" content are listed. Multipart/mixed, and
>multipart/alternative were stripped from e-mail postings before Sept.6/07.
>Since Sept.6/07, such offending e-mails are now being Content
>filtered/rejected to the listowner. No multipart, or image attachments
>are now being removed from the e-mail posting attempts?


Because you has said that no multipart or image content-types should be
accepted and that such messages should be forwarded to the listowner,
so that's what Mailman is doing. It you restore the content filtering
settings to what they were befor Sept 6, Mailman will do what it did
before Sept 6.



>Xxxxxx list Content Filtering configuration:
>
>****
>****
>
>Should Mailman filter the content of list traffic according to the
>settings below?
>(Edit filter_content)
>
>[ ] No 	[X] Yes
>
>
>
>Remove message attachments that have a matching content type.
>(Details for filter_mime_types)
>
>image
>multipart            ("trial addition of:
>                                         multipart/mixed
>                                         multipart/alternative
>                                         image/gif
>                                         image/jpg
>                    resulted in the same multipart rejection of posting".)


You are saying remove all content of type multipart/*. Thus anything
which is not a single part message of content-type image/* will be
filtered to nothing ad forwarded to the list owner per below.



>Remove message attachments that don't have a matching content type.
>Leave this field blank to skip this filter test.
>(Details for pass_mime_types)
>
>  [Blank]           ("trial addition of:
>                                         multipart
>                                         text/plain
>                    resulted in the same multipart rejection of posting".)
>
>               Also, ("trial addition of:
>                                         text/plain
>                    resulted in the same multipart rejection of posting".)
>
>
>Remove message attachments that have a matching filename extension.
>(Edit filter_filename_extensions)
>
>doc
>pdf
>exe
>bat
>cmd
>com
>pif
>ppt
>scr
>vbs
>cpl
>dat         Also, ("trial removal of:
>vcf                                   gif
>gif                                   jpg
>jpg         resulted in the same multipart rejection of posting".)


This is irrelevant, because any multipart messages (i.e. messages with
attachments) have already been completely filtered.



>Remove message attachments that don't have a matching filename
>extension. Leave this field blank to skip this filter test.
>(Edit pass_filename_extensions)
>
>[Blank]
>
>
>Should Mailman collapse multipart/alternative to its first part content?
>(Edit collapse_alternatives)
>
>[ ] No  	[X] Yes
>



This is irrelevant because all multipart/alternative parts have already
been removed.


>Should Mailman convert text/html parts to plain text?
>This conversion happens after MIME attachments have been stripped.
>(Edit convert_html_to_plaintext)
>
>[ ] No  	[X] Yes
>
>
>
>Action to take when a message matches the content filtering rules.
>(Details for filter_action)
>
>[ ] Discard  [ ] Reject  [X] Forward to List Owner  [ ] Preserve
>
>****
>****
>
>I wish to re-establish the past, correct content filtering of:
>multipart/mixed
>multipart/alternative
>image/jpg
>image/gif
>
>winmail.dat
>htm
>html
>
>Since Sept.06/07
>There have been  73   postings.
>There have been  35   multipart rejections/content filtering without 
>stripping.
>There have been  36   text/plain postings that were accepted (normal).
>There have been  02   "blank", no message body content postings slip 
>through.
>
>
>Can the missing, listed stripping actions be restored to the Content 
>Filtering
>configuration?


Sure, if you know what the pre Sept 6 settings were.

The above does not make clear what you actually want to accept, but I
suggest the following settings.

filter_content - Yes

filter_mime_types - empty

You could put 'image' here, but it isn't necessary if you do the next.
You don't want multipart because that will allow only single part
text/* and possibly single part application/*, etc. if any MUA will
create such a message.

accept_mime_types -

multipart
text
message/rfc822

This will accept multipart/* and message/rfc822 parts for further
examination, but will only accept text/* parts from within those parts.

filter_filename_extensions -

irrelevant, because no attached files that aren't text/* will make it
past accept_mime_types

pass_filename_extensions -

irrelevant, because no attached files that aren't text/* will make it
past accept_mime_types

collapse_alternatives - Yes to take the text/plain alternative over the
text/html, etc.

convert_html_to_plaintext - Yes, to convert a straight (not
alternative) text/html part to plain text

filter_action - as desired for disposition of original messages which
have all their content removed by filtering.
	
Then when you have the settings doing what you want, write them down so
the next time some list admin changes them with undesired results,
you'll know what to go back to.

Alternatively, if you have a pre Sept 6 backup of the list's config.pck
file, dump it with Mailman's bin/dumpdb and see what the various
content filtering settings were.

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