On Wed, November 5, 2014 7:39 am, Les Mikesell wrote:
On Wed, Nov 5, 2014 at 3:55 AM, Hugh E Cruickshank hugh@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 ++++++++++++++++++++++++++++++++++++++++