On Wed, 2007-11-21 at 12:29 +0100, Marcin Krol wrote: > Could this work? Pros? Cons?
Forwarding services, of which there are literally hundreds of thousands,
will be broken since the envelope-from will differ from the incoming
hostname (however you work it out).
Domestic users - millions of them - with their own domain but forced via
there ISP's outbound mailers for policy reasons (which is after all a
good thing) will fall foul of it. This category doesn't just cover
domestic users, it covers people who use email clients at work for their
own domains bu have to use their employer's outbound SMTP server too.
Servers with no rDNS or invalid or incorrect rDNS (through no fault of
the user since the providers are usually in control - allegedly - of the
PTR zones for their ranges) will fall foul of it.
If you have a problem with your DNS server, or a network problem makes
your resolver unable to do lookups to certain parts of the internet,
you'll start rejecting messages.
