On Wed, November 5, 2014 7:39 am, Les Mikesell wrote: > On Wed, Nov 5, 2014 at 3:55 AM, Hugh E Cruickshank <hugh at forsoft.com> > wrote: >>> >>> just parse the *maillog* instead >> >> That would only be effective for bounce messages that were generated >> by our mail server (in the case of messages that were immediately >> rejected by the foreign mail server when our mail server attempted to >> hand the messages off). It would not work for messages that were >> initially accepted for delivery but were subsequently returned as >> being non-deliverable. > > Are there still servers that accept undeliverable mail and generate > messages later? That behavior makes them an easy target for spammers > who send the real target address as the From: entry and will likely > get them blacklisted. Indeed, there are, and this sort of spam is called "backscatter". No need to mention that like almost everybody else I have my servers configured so that before deciding to accept message for delivery the server queries next server if further forwarding is involved, and depending on answer (deliverable/not deliverable) accepts or rejects message. This way we, even when handling forwards, will not become source of backscatter. I do have do make exemptions and if next server "lies" (says deliverable, then when message is passed to it it is accepted, but later server sends non delivery response), then I never let forwarding to these servers/domains. Even for real users who moved there. Period. I had an interesting comment from my friend about one of my exceptions. This exception is gmail.com (who at least at some point were accepting everything, then were sending you message: "user doesn't exist"). His comment was: hey, they are in business of collecting information. Of course they accept everything. And once they have the information, then they treat it as an e-mail message ;-) Valeri ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++