[Mailman-Users] Newbie Question -- Attachments (again)

[Newman, Linda (newmanld)]

Mark -- I really appreciate your answers to my questions.  

I now have the following 'pass types' allowed:
  multipart/mixed
  multipart/alternative
  text/plain
  text/html
  message/rfc822

This appears to handle plain text messages, and forwarded plain text
messages, while still dis-allowing attachments that are word files or pdf
files, executables, etc.  It also continues to translate html messages into
plain text, but if I understand your answer below, this is because the first
part of a multipart/alternative message is usually plain text, and so that's
what mailman accepts.  So, it appears that if I want html formatted messages
to also be on this list, while of course also still allowing plain text, I'd
have to either
   a) find an MUA that doesn't send html as multipart, but just as html
(suggestions?)
   b) not do any filtering of attachments.

Let me know if I have mis-understood.
-- Linda

-----Original Message-----
From: Mark Sapiro [mailto:msapiro at value.net]
Sent: Friday, October 15, 2004 3:03 PM
To: Newman, Linda (newmanld); 'mailman-users at python.org'
Subject: Re: [Mailman-Users] Newbie Question -- Attachments (again)


Newman, Linda (newmanld) wrote:

>I have read through the FAQ and tried to locate every piece of information
I
>could about MIME types and attachments, esp. reading 4.39, and I'm still
>confused, so am hoping that others can provide some simple clarification.
>
>What I'd like to do:
>   1) Prevent all attachments from going through.  (Note that if my
settings
>below are too broad and will result in rejecting messages that aren't
really
>attachments, let me know.)

See below.

>   2) Accept html, or real text format formatted messages without
>translating them to plain text.  However, if this means that other formats
>such as pdf, word, etc., would also have to be accepted, than I'd give up
on
>html.

It doesn't, you can do it - except see below regarding
multipart/alternative.

>   3) Send a notice automatically to a sender if their attachment has been
>rejected.

I don't think you can do this if the whole message is not rejected.

>   4) Send the remaining plain text part of the message to the list without
>the attachment.

You can do this, but I don't think you can get a reject notice to the
poster in this case.

>My current 'Content Filtering' options (see below) are rejecting
attachments
>and html-formatted messages.   The entire message is rejected -- even if
>there are remaining plain text parts.  RTF formatted messages are, however,
>converted to plain text.  No notice of a rejection is sent to the poster,
so
>I've configured the last option to send the message to the e-list owner, so
>that the owner could manually notify users.

This will only work if the entire message is filtered and nothing is
left for the list.

>Note that I don't seem to have access to the unix shell.
>
>My current list Content Filtering options are as follows:
>
>Should Mailman filter the content of list traffic according to the settings
>below?   -- Yes

Right.

>Remove message attachments that have a matching content type.  <none
listed>
>Remove message attachments that don't have a matching content type.  --
I've
>listed two types -- text/plain  <and, on a separate line> text/html

This won't work. It's too restrictive it will only allow single part
messages whose content-type is text/html or text/plain. You also need
to allow the text/plain and/or text/html parts from multipart
messages. Thus you must add to the above types

multipart/mixed
multipart/alternative

Also, you may wish to add

message/rfc822

to allow text/plain and text/html parts from some forwarded messages.

Note that allowing these types does not allow the entire multipart
through, it just alows its sub-parts to be examined rather than
deleted.

Further, note that if the message contains a multipart/alternative part
with both a text/plain alternative and a text/html alternative, only
the first alternative which is always supposed to be the text/plain
part.

To get HTML through to the list you either have to disallow text/plain
or make sure the HTML is not in a multipart/alternative part with a
text/plain alternative. This is difficult if not impossible to do with
some MUAs.

>Should Mailman convert text/html parts to plain text?	No

Good.

>Action to take when a message matches the content filtering rules.
Forward
>to List Owner

See above.

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