Re: [Exim] email identity usurpation

On Wed, 28 Aug 2002 10:27:18 +0100 David wrote:

> sancelot@??? said:
> > any user in my network would be able to
> > send messages over internet using a wrong email adress.
> > How to avoid this ?
> You can't.

C'mon, be fair to the guy. Clearly he's a bit behind the times and only
just discovering that e-mail headers can be faked (!). However, since this
is the exim-users list, I'm *guessing* that he is using Exim and is
looking for some kind of server-side solution. And whilst there may be no
100% guaranteed method of doing what he wants, a bit of header rewriting
at his outgoing mail server (which would, I believe, achieve what he is
essentially aiming at) would not be impossible.

Original poster: Yes, headers can be faked. This is not rocket science. If
you don't know that and you are running a mailserver, you shouldn't be.
Learning to walk before trying to run is generally a good idea. First go
and get a bit more clued up about e-mail generally, and then think about
running a server. Once you've done that, go search on this mailing
list/the net. The answers are out there.
On the other hand, if you're not running a mailserver, the exim-users list
isn't the place to be.

Tim