On Fri, 27 Mar 2009 17:24:31 -0500, Matthew Weigel wrote: >John Brooks wrote: >> I've just received this response from a large corporate email >> system regarding their claim that emails sent to them are not >> getting through even though our logs contain acknowledgements >> of accepting the mail sent. >> >> In our mail logs: >> ... status=sent (250 Message accepted for delivery) >> >> >> Their response: >> ... "my understanding of the <firmname removed> security policy >> is not to acknowledge mistakes in email addresses as a best >> practice defense against phishing and other types of email >> delivered attacks." >> >> Anybody run into this kind of logic before? > >Yes, that's part of how greytrapping works: >http://www.openbsd.org/cgi-bin/man.cgi?query=spamd#GREYTRAPPING
No. That is NOT how greytrapping works. RTFM more carefully. spamd NEVER issues a 2xx code, because it NEVER accepts any mail. > >I've seen other implementations do greytrapping for *every* invalid >address that comes through, too. And that's a great way to blacklist a genuine sender who misheard an email address and so misspelled it. S/he will never get a 5xx that flags the problem. Anyway none of the original query really related to OpenBSD. It's the provenance of whatever MTA is running (and its administrator). *** NOTE *** Please DO NOT CC me. I <am> subscribed to the list. Mail to the sender address that does not originate at the list server is tarpitted. The reply-to: address is provided for those who feel compelled to reply off list. Thankyou. Rod/ /earth: write failed, file system is full cp: /earth/creatures: No space left on device
