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Election 2006 (and beyond): Digital Copyright Canada

filtering viruses out of your mailing list

From: keb_-at-_Cyblings.ON.CA (Krishna E. Bera)
Date: 18 Apr 2000 20:07:04 -0400

A continuing thorn in my side these days is people posting
MS-Word or WordPerfect documents to mailing lists.  Often
those messages get bounced because the bloated documents
exceed the file size limit (default 40000 bytes).

However, to ensure that no unreadable junk gets through to
your mailing list, Majordomo provides a handy feature via
its config file: 

        # taboo_body           [regexp_array] (undef) <resend>
        # If any line of the body matches one of these regexps, 
        # then the message will be bounced for review.
taboo_body          <<  END
END

(You can retrieve the config file for your list by sending 
the "config <list> <password>" command to majordomo@flora.org)

To reject messages with attached wordprocessor documents 
and all binaries, place some text between the markers as shown:

taboo_body          <<  END
/^Content-Type: application\/(msword|wordperfect|octet-stream)/i
END

Send the edited config file back to majordomo@flora.org with
the command "newconfig <list> <password>".

Another (very important) step is to prepare to tell users why they
can't and shouldn't send such documents.  This is best done by consensus 
before the list is even created, but to inform new users you can add 
some text to the list's 'intro' file (using the intro and newintro 
commands, of course. See 
http://www.flora.org/flora/help/listmanagers/mailhlp3.html
for details).  Here's what i've added to the intro file for
one of my lists:


--------------------------------------------------------
- Messages containing MS-Word documents or executable files will 
  be 'bounced' (rejected), for the following reasons:

  1. they can contain viruses, risking infecting the computer
     of everyone receiving the message.

  2. they are much larger than they need to be to express the content 
     within, so they will likely exceed the size limit (40000 bytes).

- You do not want to post executables or word processor files 
  (aka 'binaries') to mailing lists, anyway:

  3. anyone using text-only terminals (e.g., basic FreeNet) cannot 
     decode binary attachments.

  4. documents in a proprietary formats put pressure on recipients 
     to acquire the technology to read those formats.  This usually 
     involves some monetary burden paid to the owner of the format. 
     Examples: MS-Word, WordPerfect, Excel, QuattroPro.

  5. binaries often require extra steps to decode.  If you want 
     people to read the document, best make it easy.

--------------------------------------------------------


Here's an alternate wording from another list.  Note that they
also discourage dual text/HTML postings:


--------------------------------------------------------
  Please do not send attachments (e.g. word processor documents, pictures,
PDF files) to this mailing list.  Why?

1. Many people cannot process them due to software incompatibility.

2. Wordprocessor documents and spreadsheets, especially from Microsoft,
can be carriers for computer macro viruses.

3. MS-Word and Wordperfect are proprietary software that produce
documents in a proprietary format.  When you use such programs and
files to communicate, you force others to acquire the wordprocessor or
similar software that is licensed to read those documents. This is
a social justice issue as you restrict people's ability to participate
in our society based upon income. Microsoft, for instance, does not make
any software for 386 or lower machines, and there are people who read the
list from even older equipment. 

4. People are more likely to read and respond to something that they
don't have to take extra steps to read.

  In addition, the mailing list software will remove non-ASCII characters
produced by some Microsoft based systems. This is most frequently the dreaded
"Smart Quotes". The mailing list software will also remove any non-text
attachments in the future.

  Please do not send in both HTML and plain text formats. Plain text will do 
just fine. For Outlook, do:
  (older versions) Tools/Options/Send/Mail sending format/Plain Text
  (newer versions) Tools/Options/Internet Email/Email sending format/
                        When sending messages, wrap text at 80 colums

  This means:
    So, go to the "tools" menu and select the "options" item.
    Inside of that, select the "Internet Email" tab.
    You'll see a box called "email sending formats"
    In that'll see a box "when sending messages wrap text at 80 columns"

    also (same form):   Character Set US-ASCII

  We recommend highly *AGAINST* using MS-Word as the editor, as you will
insert non-ASCII characters and nobody will be able to read your messages.

  For Netscape do:
unselect Edit/Preferences/Mail&Groups/Messages/Message Properties/By default send rich text

--------------------------------------------------------


It would be nice to have a feature to recognize and strip out
MIME attachments, so that the list manager's time is not taken
up dealing with bounced messages.

Hope this is helpful.  If someone wants to edit and/or format 
this as HTML and post on the Flora Help desk, that would cool.
-Krishna

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