On Mon, Mar 7, 2011 at 4:19 AM, Uros Meglic <uros.meglic@???> wrote:
> What I'm trying to do, is to rewrite the "Return-Path:" on my Exim4 smtp
> relay server. The server accepts mail from an Exchange 2007 server and
> relays it to the internet via ISP smarthost. The reason I'm trying to
> rewrite this specific header is, that per some RFC Exchange is creating
> automated out of office e-mail responses with this header present, but not
> populated, so it looks like this "Return-Path:<>". Our ISP smarthost doesn't
> accept any e-mail messages if the Return-Path is empty. I can't set Exchange
> to deliver via DNS.
It can be done, however I would strongly advise against it because you
are opening yourself up to some pretty severe routing loops. The RFC
they're referring to is:
http://tools.ietf.org/html/rfc3834
The autoresponder should not reply to any email that "has a
Return-Path address of <>". This means that if you change your return
path to non-null, and your autoresponder sends an email to a lesser
quality autoresponder, then that one will reply to yours, then yours
will reply to that one (AGAIN), then that one will reply to yours
(AGAIN), and repeat ad nauseum until yours or his bandwidth and load
spike or customer complaints or yours or his harddrive fills up.
Your ISP undoubtedly has been hit very hard with spams that were sent
to <> and so they just stop accepting it. But that's not a get
netizen. But then again. I don't know the extent of the problems they
were dealing with. But even so, the RFC's do say that you must accept
mail to <> (but I do still filter the crap out of it).
In the end, there are good points on both sides, but your ISP is
making your life difficult when it seems like they shouldn't.
--
Regards... Todd
I seek the truth...it is only persistence in self-delusion and
ignorance that does harm. -- Marcus Aurealius
