Simon Josefsson <jas@extundo.com> writes:

> Andreas Jaeger <aj@suse.de> writes:
> 
>>> QP encoding is to avoid the article to be mangled.  Though a message
>>> contains only ASCII, lines starting with "From " or so be mangled.
>> 
>> I see - but that's rather unfortunate.  Is there no way to avoid this?
>> I'd rather don't use QP.
> 
> Then you'd be breaking the PGP/MIME specification, and the receiver
> probably couldn't validate your message.
> 
> 3.  Content-Transfer-Encoding restrictions
> 
>    Multipart/signed and multipart/encrypted are to be treated by agents
>    as opaque, meaning that the data is not to be altered in any way [1].
>    However, many existing mail gateways will detect if the next hop does
>    not support MIME or 8-bit data and perform conversion to either
>    Quoted-Printable or Base64.  This presents serious problems for
>    multipart/signed, in particular, where the signature is invalidated
>    when such an operation occurs.  For this reason all data signed
>    according to this protocol MUST be constrained to 7 bits (8- bit data
>    should be encoded using either Quoted-Printable or Base64).

But this means that I still can use ASCII for 7bits and do not need to
use QP for 7-bit only data.

Have a look at this email - it's signed, contains AFAIK no 8-bit data
and is still QP.  That's the problem I see.

Thanks for the explanation I now accept that I have to live with QP as
soon as my emails contain 8-bit data.

Andreas
-- 
 Andreas Jaeger
  SuSE Labs aj@suse.de
   private aj@arthur.inka.de
    http://www.suse.de/~aj