[Mimedefang] Content-Type multipart/mixed and multipart/related

Jobst Schmalenbach jobst at barrett.com.au
Wed Aug 24 03:47:53 EDT 2005


I have a problem with 

   Content-Types: multipart/mixed and multipart/related

togther with thunderbird, HTML based email and mimedefang!

All of us use thunderbird, we dont use anything else (other than squirrelmail).
We get a lot off HTML based email with a number of pictures/tables/divisions.

I created a message using thunderbird with a number of different HTML based features to
test our mailserver setup and to change some things within Anomy::HTMLCleaner to make
it more appropriate for (our) business type use. 

Into the test email I put a division, a table and a couple of images.
The CORRECT (as it should be displayed) email can be seen as an image at


and the source


When I send this from an outside machine to myself, mimedefang tells sendmail to change the header:
Aug 24 14:33:00 sendmail[23835]: j7O4WxqI023835: Milter change: header Content-Type: from multipart/related;\n boundary="------------030706090001050109080902" to multipart/mixed; boundary="------------030706090001050109080902"
although HTMLCleaner did not change a thing (or any other part of mimedefang) within the email.
This is because (reading the code of "sub anomy_clean_html" in mimedefang.pl) 
it always does this. I guess it would be hard to determine if something got changed.

However, this makes it impossible for thunderbird to read as it expects multipart/related.
thunderbird appends the images. (outlook and any other email client display them properly).

My changed setup of Anmoy::HTMLCleaner involves:

    if (!$hash) {
        $hash = { };
        $hash->{"Paranoid"} = 0;
        $hash->{"NoWebBugs"} = 1;
        $hash->{"NoExeLinks"} = 1;
        $hash->{"UnknownTagsOK"} = 0;

    and in the code of Anmoy::HTMLCleaner line 392

#    "div"   => \$r_style,  # Disabled because of Eudora rendering bugs.
    "div"   => 1, # we dont use Eudora

which off course lets inline images and division through.

Now from my understanding reading


multipart/related is correct!

I have been in talks with the delevelopers of Thunderbird as you can see at


What can be done about this as this is rather annoying. I do not want to loose
the features of HTMLCleaner to get rid of all the nasty stuff in HTML and
I like the customisation of mimdefang.


"XP: If you are nine years old you are just going to love it.  If you're a few years older you'll resent the choking paternalistic atmosphere of vapid gee-whiz kiddie entertainment (babysitting), euphemism and fake-friendly bullying."

             __, Jobst Schmalenbach, Technical Director
   _ _.--'-n_/   Barrett Consulting Group P/L & The Meditation Room P/L      
 -(_)------(_)=  +61 3 9532 7677, POBox 277, Caulfield South, 3162, Australia

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