[Mimedefang] Bare returns in message body

[Les Mikesell]

On Wed, 2005-11-09 at 07:35, David F. Skoll wrote:
> Joseph Brennan wrote:
> 
> > We're interested in patching mimedefang.c to do this, but have this
> > funny feeling that there is a good reason David removes them.  What
> > would it break?
> 
> I can't remember why I remove them (it's been a while), but I did
> have a good reason.
> 
> RFC 2821 says:
> 
>    In addition, the appearance of "bare" "CR" or "LF" characters in text
>    (i.e., either without the other) has a long history of causing
>    problems in mail implementations and applications that use the mail
>    system as a tool.  SMTP client implementations MUST NOT transmit
>    these characters except when they are intended as line terminators
>    and then MUST, as indicated above, transmit them only as a <CRLF>
>    sequence.
> 
> RFC 2822 says:
> 
>    - CR and LF MUST only occur together as CRLF; they MUST NOT appear
>      independently in the body.
> 
> Note that these are MUST NOT requirements, not SHOULD NOT requirements.
> So in theory, it is OK to reject such messages.

The RFC's deal only in 'wire level' representation during the SMTP
conversation.  Mail transports/delivery agents normally convert
to/from the local line endings.  I don't think there is any such
thing as a universal file representation (the MIME folks really
missed a need here).   Since MimeDefang's copy is sort-of still
in transport but is actually a local file copy it is bound to be
wrong for something.

-- 
  Les Mikesell
    les at futuresource.com