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Re: Attachment altered because of 7 bit (none) encoding.



On 2005-12-05 09:33:56 -0600, Bo Peng wrote:
> I noticed that some of the .lyx files I sent via mutt were altered (an
> extra dot is added) at lines with a leading dot. I did some
> research/experiments and find that:
> 
> 1. .lyx is a pure text file format that tends to have lines with leading dot,
> 2. without an .mime.types entry, mutt does not encode .lyx file.
> 3. According to RFC 821, such lines will be added an extra dot

and removed on the other side.

> 4. Mail clients may or may not remove these extra dots.

Mail clients shouldn't do anything. You probably have a broken MTA.

> After I add 'application/lyx lyx' to my .mime.types, mutt encodes the
> attachment and the problem disappears. However, I do think mutt's
> behavior is unsafe and pine's treatment of this problem is better:
> 
> http://www.washington.edu/pine/faq/attachments.html
> 
> 7.2 Why does Pine encode text attachments?
> 
> Pine uses MIME's Base64 encoding for all attachments, including text,
> in order to assure that they are not modified in transit. The goal is
> make sure that sending file attachments in Pine is as dependable as
> using FTP.

This is a bad idea. This prevents from doing simple mail-filtering
without MIME decoding. I personally reject such messages for bad
behavior. Quoted-printable is sufficient and mail-filtering is
still possible at least for English words.

> 2. Is it a good idea to make this the default behavior of mutt?

No, this should not be the default behavior.

-- 
Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <http://www.vinc17.org/>
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Work: CR INRIA - computer arithmetic / SPACES project at LORIA