Re: [exim] strange quoted-printable problem

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Autor: John W. Baxter
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Dla: exim-users
Temat: Re: [exim] strange quoted-printable problem
On 5/1/2005 15:24, "Dominique" <exim-users@???> wrote:

> Recently I've run into a peculiar attachment problem. A client of mine is
> receiving e-mail attachments from its customers. The attachments may 8-bit
> with embedded JPEG images. Thus the beginning of the file is 8-bit text with
> CR LF characters and the end binary.
>
> Unfortunately some mailers (Windows based) appear to attach these as
> quoted-printable. At some point during the mail transfer the binary 0D and
> 0A characters are rewritten into new line characters in the quoted-printable
> data. This in turns results in corrupt JPEG data.


MS Outlook, with the global preference set to do styled text as RTF rather
than HTML, sends many attachments as Quoted Printable. That would be fine
(they tend to be smaller in many cases, like PDF files than Base64 encoded),
but Outlook doesn't do Quoted Printable correctly.

It doesn't take Exim to munge these...Outlook does so on its own. (The
attachments are equally broken passing through the mail system at mac.com.)
With a sender you can work with (fewer than all), suggest setting that
global setting to HTML for styled text. That will switch the favored
attachment encoding to Base64. (I don't know why, I'm 30 miles or so from
Redmond...too far for mind reading to work well. Personally, I don't see
the connection.)

With senders you can't work with, try having your aggrieved recipients make
the contact, and the setting suggestion.

We ran into this last summer, with PDFs from one sender to one recipient.
The change to Outlook settings took care of the problem. [Creative use of
Google will find the information, but it does take care in setting up the
search to have it show up near the first result page.]

Naturally, Outlook itself understands the broken quoted printable. Outlook
Express doesn't. :-)

--John