[Mailman-Users] Digests and HTML-enhanced email

[Lindsay Haisley]

I host a list for about 700 autoharp musical enthusiasts on Mailman
2.1.12.  The subscribers are by and large somewhat elderly and non
techie, and to most of them an explanation of the difference between
HTML-enhanced email and plain text email would be unintelligible
geek-speak.  I recently received the following email from one of the
subscribers:

> "Scrubbed" messages as they appear in my cyberpluckers DIGESTS:
> This type of problem is perhaps a bit over 6 months old, and evidently
> is caused by the manner in which some people have tried to attach
> their message to their cyberplucker posting.
> 
> How can this problem be resolved?    THANKS ... Drew Smith
> *******************************************************
> 
> Message: 25
> Date: Fri, 7 Oct 2011 08:42:29 -0700
> From: "foo bar" <.......>
> To: Cyberpluckers at autoharp.org
> Subject: Re: [CP] Intro
> Message-ID: <a0ffed34-525e-40a5-88c6-4b78dbef2df8 at blur>
> Content-Type: text/plain; charset="us-ascii"
> 
> An HTML attachment was scrubbed...
> URL:
> http://www.autoharp.org/mailman/blah/blah/..../attachment.html
>
> ... <snip> ... other examples

I took a look at the list archive and indeed the email appears in the
archives also with only a link to the attachment, which is the
HTML-enhanced message, visible as HTML code.  There's no plain text
version in the archive.

I explained to the subscriber, and to the list admins, that this (and
similar) posts were probably HTML-only posts, and that, absent a plain
text rendering in a multipart email, the list server had no way to
generate a plain text version, and that including multiple HTML-enhanced
emails in a digest was problematic and not going to work very well, if
at all.  The list admins are aware that plain text is the appropriate
format for posting to a mailing list, but subscribers come and go from
this list, and as I said, many don't understand such things, and it
seems that there are a number of mail programs out there which will
generate an HTML-enhanced email without an accompanying MIME text/plain
version.

The list is configured with mime_is_default_digest set to MIME, which I
assume sends digests with each post as a separate attachment (I've never
subscribed to the digest for this list, so I don't really know).  I had
assumed that this might address this problem, but apparently not.

One of two things needs to happen.  Either the list server should refuse
and bounce posts with no MIME text/plain part, or some more intelligent
configuration of Mailman needs to be available so that posts within a
digest will render properly under these circumstances.  Maybe a more
recent version of Mailman can do this, I don't know.  Any suggestions
would be appreciated.

I rather dislike HTML-enhanced email (to put it gently).  There's no
fixed standard for it, and what renders one way in one mail reader
renders some other way in another mail reader, and it confuses the hell
out of list servers.  But people will use it, increasingly it seems, and
insist on doing so, so somehow this kind of problem needs to be dealt
with.

-- 
Lindsay Haisley       | "Real programmers use butterflies"
FMP Computer Services |
512-259-1190          |     - xkcd
http://www.fmp.com    |