On Saturday 31 January 2009 09:22:28 Terry Carmen wrote: > Melvyn Sopacua wrote: > > On Saturday 31 January 2009 08:03:17 Wietse Venema wrote: > >> Melvyn Sopacua: > >>> The problem is that postfix will see "success" initially: > >>> > >>> - client sends > >>> - postfix receives > >>> - postfix relays, gets OK > >>> ----> postfix deletes queued message > >>> - exchange checks quota, decides mailbox is full > >>> - exchange sends DSN to client > >> > >> Use reject_unverified_recipient, with a persistent database. This > >> will check the Exchange response BEFORE accepting mail, and will > >> avoid hammering the Exchange server with repeated requests. > >> > >> http://www.postfix.org/ADDRESS_VERIFICATION_README.html > > > > VRFY i...@example.com > > 252 2.1.5 Cannot VRFY user, but will take message for <i...@example.com> > > > > yet, mailbox is full and DSN will come few seconds after mail is > > accepted. Judging from the 2xx response, this means to postfix that VRFY > > succeeded, so the problem persists. > > This is a classic example of trying to fix a people problem using > technology. Exchange is broken. It is accepting then losing messages > that it can't deliver. You are not the exchange admin, so you can't fix it.
Yes, I already mentioned that. I'm not trying to fix their problem, I'm trying to provide redundancy, until their problem is fixed. It could similarly be used to catch false positives of a spam filter, until it is trained finer. -- Melvyn Sopacua
