Author: James P. Roberts Date: To: Sheldon Hearn, barryp CC: exim-users Subject: Re: [Exim] CRLF input through pipe causes mangled headers
> > I used tcpdump to take a look at the traffic Exim was generating > > both for SMTP and LMTP delivery of these CRLF terminated messages,
> > and found that Exim *is* modifying the message bodies, adding an
> > extra CR, so the lines end up transmitted over the wire with CRCRLF
> > terminations.
> >
> > So Exim is already violating point #1, but it has to, because
> > as Philip said - it's a Unix world, and most files have just LF
> > termination. Exim usually needs to add CR to make it legal SMTP -
> > it's just that in this case, they're already there, but unfortunately
> > Exim is just blindly adding some more.
>
> Hang on, you're misunderstanding the results you see. You're looking at
> the message "in transit", where it's governed by network transport
> rules. Those extra CRs you're seeing are removed at the other end of
> the transport pipe, as mandated by the standards.
>
> What we're talking about, with respect to changing message bodies, is
> that Exim shouldn't make changes that are visible OUTSIDE the scope of
> transport. This is also mandated (to varying degrees depending on
> context) by the standards.
>
> Ciao,
> Sheldon.
Ah. Thanks for the clarification. I completely agree with that concept.
Just as, for example, using SSL to encrypt a message in transport, which
obviously modifies things in transit, but make no changes to the contents
coming out the other end of the pipe. Cool. I think I get it.
