Re: [Evolution] Quick question on Filter on Subject...

[guenther <guenther rudersport de>]

On Sun, 2004-02-08 at 22:38, David Woodhouse wrote:
> On Sun, 2004-02-08 at 22:03 +0100, guenther wrote:
>
> > Gah. Sure, when redirecting mails, the other person acts like he does
> > not exist and the mail gets directly to you. After all, there should not
> > be a difference, if a human or a .forward file redirects mail... ;)
>
> There should be a difference -- RFC2822 says Resent-* headers should be
> added if a human does it, but not if a .forward file does it. See §3.6.6

Oh well, thanks for the info, David. I didn't know about the exact
Resent-* headers details.


> > Well, agreed. Any of this filters can fail in some weird situations. I
> > should not have claimed no failures at all.
>
> Actually, filtering on Sender: can indeed give the same false positives
> as List-Id: if the MUA of the person resending the message actually
> implements RFC2822 §3.6.6 properly and keeps the same Sender: field when
> resending a message.

That's about what I meant.

So the Sender: header actually is expected to be removed when a user is
involved? Otherwise filtering on Sender: header additionally must check
the absence of a Resent-*: header to exclude user forced forwards.
(Nope, I have not read RFC 2822 entirely... ;)


> What's better is to use the SMTP reverse-path -- which will often be
> found in the Return-path: header. Although I use that myself for all
> lists, I tend not to recommend it because different MTAs may not add it,
> or may do something different. 

Filtering on List-Id: headers [1] works perfectly for me so far. That's
what it is meant for after all, AFAIK. I tend to get forwards rather
than redirects...

...guenther


[1]  list-post: for some mailing list software, as the List-Id: header
is missing...


-- 
char *t="\10pse\0r\0dtu\0  ghno\x4e\xc8\x79\xf4\xab\x51\x8a\x10\xf4\xf4\xc4";
main(){ char h,m=h=*t++,*x=t+2*h,c,i,l=*x,s=0; for (i=0;i<l;i++){ i%8? c<<=1:
(c=*++x); c&128 && (s+=h); if (!(h>>=1)||!t[s+h]){ putchar(t[s]);h=m;s=0; }}}