On 5/6/2008 10:24 AM, David le Blanc wrote: >>> BTW, I find recipient validation is not as important as you would >>> imagine. Certainly mail to unknown users is normally bounced >>> immediately, but that merely assists in harvesting attacks.
>> I assume you mean REJECTed, not bounced... but it is a misconception >> that it 'assists in harvesting attacks... > The difference is not important here. Your ignorance only contributes to the problem. > Any legitimate sender will always get an NDR for a failed delivery. How do you tell a legitimate from illegitimate sender? One way is through SAV, which if you implement blindly will wind up getting you blacklisted if you ever get hit by a real dictionary attack. > The original comment was specifically describing the choice made > between ASSP (or any other product) rejecting the incoming email at > the perimeter based on recipient validation, versus accepting the > mail for processing and later issuing an NDR due to an invalid > recipient. It is IMPOSSIBLE to send an NDR AFTER you have accepted the message for final delivery. Do you get that? IMPOSSIBLE. An NDR is NOT an EMAIL message, it is an SMTP What you are doing is sending BOUNCE messages, which in this case is called BACKSCATTER. > Reiterating, I choose NOT to 'REJECT' email based on recipient, but > rather forward to the email to the appropriate end point which can > issue an NDR, allowing me to, at some later point in time, to review > the email, possibly forwarding to the intended (or appropriate) > recipient. If you are simply RELAYING mail, then that is an entirely different animal, and your description is sorely lacking. If, however, you are doing what it *appears* you are doing - accepting mail on the server that is authoritative for the recipient then BOUNCING certain messages LATER - as opposed performing an SMTP REJECT at the perimeter - then you ARE, whether you choose to ACCEPT it or REJECT it, engaging in BACKSCATTER, and are a part of the problem rather than the solution. > This appears to be little more than misinformed and thinly veiled > personal attack. What possible reason would I have to personally attack you? I don't *know* you, all I have to go by are your written words, which - again - *appear* to be saying that you are engaging in backscatter... If this is not the case, then you should learn to be more precise with your language. > NDR: (aka bounce) > http://www.webopedia.com/TERM/N/NDR.html Yes... an NDR (which is essentially an SMTP REJECT) can ONLY be performed AT THE PERIMETER on the server that ... Did you even read the references you linked to? Here's a pertinent snip: "Types of backscatter: * Misdirected bounces from spam runs, from mail servers who “accept then bounce” instead of rejecting mail during the SMTP transaction." This *appears* to be what you are doing. You may be doing some work to try to limit the damage - you said something above about 'legitimate' senders - but it doesn't matter, what you are doing - *if* this is indeed what you are doing - is WRONG. > And a hard one for you... > > Catchall Email Addresses; > http://www.homebiztools.com/questions/catchall.htm Oh, I know what a ctach-all is, I assure you - and I also know why they are very, very BAD in 99% of cases (there *are* some legitimate uses for them, but NOT on a normal mail server that gets real mail). Your ignorance would be amusing, were it not for the fact that you are making the spam problem worse. Do you really want to continue this? -- Best regards, Charles ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Assp-test mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/assp-test
