Quoting Jaap Winius <jwinius@umrk.to>:

> Quoting Michael M Slusarz <slusarz@horde.org>:
>
>>> Could someone please explain how to avoid quoted printable for the
>>> content transfer encoding of the message body? I'd like to see IMP
>>> v4.1.5 use 8-bit MIME negotiation whenever possible, but that doesn't
>>> seem to be happening in my case.
>>
>> Um, why?  8-bit encoded messages are illegal per the RFCs so IMP will
>> *never* send a message 8bit.
>
> Sorry, but I was referring to transfer encodings that are used to  
> represent 8-bit binary data with characters from the 7-bit ASCII  
> character set. See RFC 1652. It's good for supporting characters  
> outside the US-ASCII range.

RFC 1652 deals with SMTP servers.  This is irrelevant for IMP.  You  
need to look at RFC 2822 which defines the format for a valid e-mail  
message and, more specifically, Section 2.1 which states:

2.1. General Description

    At the most basic level, a message is a series of characters.  A
    message that is conformant with this standard is comprised of
    characters with values in the range 1 through 127 and interpreted as
    US-ASCII characters [ASCII].

> Exim4 has support for this with settings such as "accept_8bitmime".  
> I know it works, because when I telnet to my server and issue an  
> EHLO command, one of its responses will be "250-8BITMIME". As for  
> clients, Alpine 0.99 can be configured with  
> "Feature-List=enable-8bit-esmtp-negotiation". If, e.g. I then use  
> Alpine
> to send a message with the UTF-8 character set and some Cyrillic  
> text, it will include the header "Content-Transfer-Encoding: 8BIT".

Sure, and IMP views 8bit messages just fine also **if and only if**  
the 8bit characters survived transport.  But there is absolutely no  
way at the current time to ensure that transport from server A to  
server B will not munge 8bit characters.

Setting a preference in an MTA or MUA only ensures that 8bit transport  
will work on your local server.  But it is impossible for you to  
guarantee that any other server will work correctly.

> When viewing the message headers with IMP4, it's the very first one  
> displayed. Right now, the messages I send all have  
> "Content-Transfer-Encoding: quoted-printable".

You must encode (either base64 or Q-P) to create a RFC 2822 complaint  
message.  This is what we do.

michael

-- 
___________________________________
Michael Slusarz [slusarz@horde.org]

