[Mimedefang] base64 to text

[Kees Theunissen]

On Mon, 25 Sep 2017, Dianne Skoll wrote:

>On Mon, 25 Sep 2017 10:46:01 -0700
>"Michael Fox" <news at mefox.org> wrote:
>
>> I'd like to be able to deliver HTML and Base64 messages to those
>> clients.
>
>You can do it by throwing away non-text/plain parts where a text/plain part
>exists.

Be careful with that. In an ideal world "multipart/alternative" MIME
parts would supply differently formatted versions of the same message.
But I have seen way too much messages where the plain text version
is only used to inform me that my mail client doesn't support html-mail.

A particular sender "Nederlandse Spoorwegen" (Dutch Railways) comes
in my mind, but there might be other brain death senders.

A typical message structure:

  From: ....
  To: ....
  Date: ....
  Subject: ....
  Message-ID: ....
  MIME-Version: 1.0
  Content-Type: multipart/alternative;
      boundary="----=_Part_4211042_445498562.1498036383123"

  ------=_Part_4211042_445498562.1498036383123
  Content-Type: text/plain; charset=UTF-8
  Content-Transfer-Encoding: 7bit

  Dear reader,

  Your email program does not support HTML mail. Follow the link below
  for the online version of this email so that you can read this email.

  < some URL inserted here >

  Sincerely,
  Dutch railways

  ------=_Part_4211042_445498562.1498036383123
  Content-Type: text/html; charset=UTF-8
  Content-Transfer-Encoding: quoted-printable

  < html version of the message inserted here. >

  ------=_Part_4211042_445498562.1498036383123--


Ofcourse my mail client does support html mail, I only configured it to
prefere the plain text version.
Do I need to say that the URL mentioned in the plain text part is only
valid for a few months?

This migth not be a problem in most cases as the text/plain part
generally _is_ a valid representation of the message, but be aware that
you risk to delete unique contents when you throw away a non-text/plain
message part.


Regards,

Kees Theunissen.

-- 
Kees Theunissen,  System and network manager,   Tel: +31 (0)40-3334724
Dutch Institute For Fundamental Energy Research (DIFFER)
e-mail address:   C.J.Theunissen at differ.nl
postal address:   PO Box 6336, 5600 HH, Eindhoven, the Netherlands
visitors address: De Zaale 20, 5612 AJ, Eindhoven, the Netherlands