--On Thursday, December 04, 2003 17:45:34 +0000 Chris Edwards <chris@???> wrote:
> We thought about using exiscan's rexexp feature to detect and reject such
> messages during the dialog. But we couldn't get this to work. Regexp
> looking for NULL never triggered.
Hmm. I've had no problem with this one:
deny log_message = NUL in body
message = Unescaped NUL character in message body\n\
(See RFC 2822, section 2.3; and RFC 2045, sections 2.7 & 2.8)
condition = ${if match {$message_body} {\N\x00\N} {yes} {no}}
Note that it is necessary to use the \N escape to prevent the \x00
from being converted by exim's string expansion before it can be
parsed by the regexp routines.
> Nowadays we deliver to those destinations using a transport filter which
> uses "tr" to bin the damm things:
>
> transport_filter = /usr/bin/tr -d \\000
Personally, I'd rather reject these messages. Every one I've seen so
far has been spam. And if it isn't spam, the sender needs to know that
their MUA is broken. (While I'm generally an advocate of the 'be liberal
in what you accept and conservative in what you send' philosophy; I've
become considerably more conservative in what I accept in email.)
-Pat
