On Sun, 2010-05-09 at 14:34 +0100, Jeremy Harris wrote:
> On 05/09/2010 08:16 AM, Ron White wrote:
> > On Sun, 2010-05-09 at 12:31 +1000, Ted Cooper wrote:
> >> This doesn't seem like a job for address rewriting. I just use a catch
> >> all router at the end with specific conditions.
> >>
> >> I have a very old setup that will catch all crap sent to a domain I
> >> specify in a directory. I should have changed this ages ago into
> >> something more useful, but not many people use a catch all so it's not
> >> something I want to change.
> >>
> >> Anyway, If I have a domain I want to catch all on, I "touch
> >> /etc/exim/catchalladdress/<domain to catch>" and then this router
> >> sitting at the bottom of my routers does the rest:
> >>
> >> # last router before default reject
> >> catchall:
> >> driver = redirect
> >> domains = dsearch;/etc/exim/catchalladdress
> >> data = catchall@$domain
> >> cannot_route_message = Unknown user
> >>
> >> .. well, except that I also add an alias on that domain called
> >> "catchall" which redirects itself to whatever account you want, OR just
> >> create an account called catchall that collects everything.
> >>
> >> If you want, you can keep the original recipients by adding them as a
> >> header.
> >>
> >> I only run a catch all so I can make up email addresses on the fly on a
> >> spam/bacon trap only domain. Very useful for tagging which site which
> >> addresses were entered into. Other than that, they're evil.
> >>
> >>
> >>
> > Hi Ted,
> >
> > Thanks for that. It's a little more complex in my set up because Exim
> > handles mail for:
> >
> > 1. Locally hosted domains and recipients
> > 2. Remote/relay to domains and recipients
> > 3. Remote/relay domain may also have users locally hosted user
> > accounts(such as postmaster/abuse/notifications).
> >
> > The catch-all is dynamic. The user can change the local part
>
> The we're talking at cross-purposes. Catchall, to me, means
> that any local-part (for some particular domain) is accepted.
That's right. The issue is the domain may be local or remote and the
dynamic address needs to be verified.
>
> which means
> > (1) the final catch-all recipient needs to be verified so we don't
> > accept mail for something we can't deliver (2) that catch all could be a
> > locally routed account, a remote smtp destination (sub classes of 'by
> > ip, by hostname, by mx) (3) the per-user settings of the destination
> > catch all, which are set in the ACL's, would not be honoured potentially
> > leading to spam/viruses flowing through unchecked. As far as I
> > understand it using a router to do it means that you have accepted the
> > message at that point.
>
> Not if you do recipient-verification in your RCPT acl. That calls the routers.
But for locally hosted 'virtual' users I'm doing this in an ACL and
checking against a mysql database. The reason for this is my lowest
'unit' is a recipient, not a domain. fred@??? may be a locally
hosted user belonging to domain foo.bar, but randy@??? may be on a
different host. The 'host' data could be of three types, an ip address,
a hostname lookup or an mx lookup. The consensus was mixed when I asked
about this and we arrived at an ACL being the best way to control this.
Relay destinations are verified with a callout.
>
> - Jeremy
>
I'm working on plan-b, but thanks for the reply. Appreciated.
