On 24 Jun 2002, at 9:02, Dave C. wrote:
> On Sun, 23 Jun 2002, Yura Pismerov wrote:
> > Finally I figured (thanks to Communigate Pro mailing list) what I'd
> > like to have to fight spammers that pretend to be somebody from our
> > domain. Is there way to reject messages without SMTP AUTH if
> > return-path header contains local address ? Here is excerpt from
> > Communigate Pro manual. I need the same for Exim. Is it possible ?
> Unless you are an open relay, spammers (who arent your customers)
> shouldnt be able to send mail through your server anyway. If the
> spammers are your customers, then this wont stop them anyway.
> If you are trying to stop just spam coming TO your domain, which also
> forges a sender address in your domain, this might have some limited
> use. But surely not a very high percentage of the spam you receive
> falls into that category.
> If a spammer wants to forge sender addresses in your domain name,
> there is currently no technical way to stop them from doing so, using
> servers which are not yours - only legal after-the-fact methods (eg,
> sue them for forgery)
also, be very careful on this question: a well known ISP set up a
filter to exclude messages with "internal" from coming from outside.
Unfortuinately this set-up filtered out also message coming
throught lists ...
the net result has been that in a week it lost about 40% of its
customers, taht could no longer receive e/mails from lists.
Leonardo Boselli
nucleo informatico e telematico
Dipartimento Ingegneria Civile
Universita` di Firenze
V. S. Marta 3 - I-50139 Firenze
tel +39()0554796431
cel +39 3488605348
fax +39()055495333
http://www.dicea.unifi.it/~leo
