[Mimedefang] Bare returns in message body

David F. Skoll dfs at roaringpenguin.com
Wed Nov 9 08:35:49 EST 2005

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>

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.



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