On Sat, May 9, 2009 at 7:38 PM, Wietse Venema <wie...@porcupine.org> wrote: > Curtis: >> > Companies that provide out-sourced email filtering service often >> > don't have up-to-date recipient lists. Instead they verify addresses >> > in real-time. ?The Postfix implementation of this is described in >> > http://www.postfix.org/ADDRESS_VERIFICATION_README.html. ?It supports >> > routing overrides, positive caching and negative caching. >> >> Yeah, I looked at that option too... but the part about getting black >> listed didn't sound too appealing. ?(Some clients will be able to >> whitelist our server's IP, but we expect that a few of our clients >> will be on shared hosts were they will have little to no control of >> such things.) > > Blacklisted by whom? By your own customer? That would be stupid.
It would be unintentional, of course, and not by any action of our direct customers. As I said, there are millions of domains out there that are hosted in shared hosting environments. Our customers that are in these environments have little to zero control over the policies of their hosting providers. Coincidentally, I own a shared web hosting company and our automated systems actually did unintentionally black list a spam filtering service (not for this reason but for another), so I have a little experience with how things like that happen. But, perhaps we could experiment with this.. the idea that doing address verification might cause our servers to get black listed by the receiving server was something I read on the page you referred to ( http://www.postfix.org/ADDRESS_VERIFICATION_README.html ). Curtis > > Wietse >
