Wietse Venema:
> Rainer Frey (Inxmail GmbH):
> > On Friday 10 October 2008 15:46:46 Wietse Venema wrote:
> > > Rainer Frey (Inxmail GmbH):
> > > > On Wednesday 08 October 2008 00:52:10 Noel Jones wrote:
> > > > > Will the FILTER action accept an empty nexthop?
> > > >
> > > > It seems it does not (at least not correctly). If the nexthop is empty,
> > > > it seems to assume the local host (which of course leads to "mail loops
> > > > to myself" if the recipient domain is not handled by postfix).
> > >
> > > This is incorrect.
> > >
> > > Postfix will complain about a mail loop REGARDLESS of the nexthop
> > > information unless you "filter" the mail to a non-SMTP TCP port,
> > > or unless you change the smtp_helo_name on the smtp delivery agent.
>
> Oops, that should be myhostname.
>
> > So will the FILTER action accept an empty nexthop (and determine the
> > nexthop
> > from the recipient address domain) IF I change the smtp_helo_name? We
> > tested
> > this and came to the conclusion that it doesn't work, but I don't have the
> > logs anymore, and I couldn't swear we didn't make a mistake and didn't have
> > the smtp_helo_name changed at that moment.
>
> There are two loop detection mechanisms. You override one with []
> around the next-hop domain. This mechanism is based on MX lookups.
> You override the second one with myhostname, or a non-standard TCP
> server port. This mechanism is based on comparing the server's
> EHLO/HELO reply with the client's myhostname.
I was a little too quick with responding.
Loop detection is turned off when sending to a non-SMTP TCP port;
that's both loop detection by comparing the destination's IP
address(es) against the MTA's own IP address(es), and loop detection
by comparing the SMTP server's EHLO/HELO response against the SMTP
client's myhostname.
Wietse
