paul(_at_)pscs(_dot_)co(_dot_)uk (Paul Smith) wrote on 22.05.01 in
<5(_dot_)1(_dot_)0(_dot_)14(_dot_)2(_dot_)20010522204602(_dot_)0669c590(_at_)192(_dot_)168(_dot_)57(_dot_)100>:
The MTA is one we wrote ourselves, so we'll add an option to it to either
accept ONLY CRLF as line terminators in messages (the new default) or
accept any combination of LF, CR, CRLF (or even LFCR which we've seen in
one instance from an MUA a couple of years ago..)
We may make this a bit smarter in the future. One thing we've spotted in
this case is that the message header is all formatted correctly, but the
message body has bare CRs in it, so we may say that if the header is
correct then we'll assume the rest of the message should be, but if the
header uses just CRs or just LFs then we'll assume the rest of the message
is the same as well.
One technique I've seen mentioned in a previous thread about this, and
which at least looks as if it should work well, was to look at the SMTP
commands the client sends.
I've used this technique in the past. It did not work well in practice.
In many implementations message and command handling are largely divorced
from each other, and when one is broken it isn't predictable by looking
at the other.
Ned