[Mailman-Users] Questions about Content Filtering

[Robert Heller]

At Wed, 20 Aug 2014 09:34:17 -0300 Nancy <cybergram at eastlink.ca> wrote:

> 
> Hi folks, I am not very technically inclined and I'm the co- listkeeper for a group. We have had some problems lately and we were wondering
> what would happen if we made changes to the Content Filtering section of the Admin page?
> 
> If :
> multipart/mixed
> multipart/alternative
> were removed would the listkeepers, as owners of the group receive bounces from everyone who tried to send formatted text?
> 
> If these two lines were changed from "Yes" to "No" what would happen?
> 
> Should Mailman collapse multipart/alternative to its first part content?  No Yes X<http://lists.oso-aa.org/mailman/admin/grow/?VARHELP=contentfilter/collapse_alternatives>
> 
> Should Mailman convert text/html parts to plain text? This conversion happens after MIME attachments have been stripped. No Yes X
> 

The *best* option would be to:

1) reject (or moderate) 'pure' HTML messages. 
2) Strip text/HTML parts off.
   Most (all?) *decent* E-Mail clients send both a text/plain and a text/HTML
   version of the message (multipart/alternative). Generally, the text/plain
   is 'sufficient' -- it contains the *text* of the message, without the
   (unnecessary!) formatting (eg fonts, colors, etc.). *Some* mailers deal
   with 'bold' using old-school ASCII tricks (like *this is bold*).
   
Unfortunately, many mailers / computers (including cell phones and tablets), 
use non-ASCII character sets (not that they need them really, esp. for 
*American* English), so lots of 'common' characters like quote marks, 
aposthophes, and some other puncuation characters show up as UTF-8 characters 
that don't display well with 7-bit ASCII mailer programs.



> Examples of our current problem:
> 
> 
> 1.This    at the end of every sentence & inserted in several places in sentences:
> Louise can't get email.  
> 
> 2. One continuous paragraph arrives when the sender had made appropriate paragraphs

Unfortunately, many modern E-Mail clients no longer insert line breaks and 
expect the *receiving* E-Mail client to 'wrap' lines, depending on the display 
width.  There is not much you can do about this, other than rant at the E-Mail 
client authors, who are not going to listen to you.

> 
> 3. Complete gibberish:
> MLN€13:46 UTC−4
> \Ý[˜]Z\™NˆÚ\œšYHÛۙH\Ú\œšYP at arthlink.net>
> ؚ™]ˆ°ê\ˆÙ[ÛÛYHÈԓÕΈ[\ܘ\žHMentor hi from Jessi first nine days
> > 
> > Hi Sherrie
> € Day 10 :)
> ‚F†沭÷Rf÷"6†V6¶­ær­ââÆ÷fRF†Rw&÷W. Reading the threads in my inbox every day <http://lists.oso-aa.org/mailman/admin/grow/?VARHELP=contentfilter/convert_html_to_plaintext>
> 
> Are these  problems caused by many people now using cell phones & tablets to send email?
> 
> Thank you for your patience & any help you might provide.
> 
> Nancy
> 
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>                                                                                                   

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