Last night I performed a crude survey in an attempt to find out something about the proportion of SMTP mail relays which permit promiscuous relaying in NZ. The methodology is by no means flawless, but it might give an idea of the scope of the problem. If anything, the proportion of mail relays which are open is understated, due to: + an incomplete list of mail relays in NZ to check; + a rather nasty SMTP implementation hacked together for this purpose that isn't very flexible and makes various poor assumptions; + mail relays which were broken at the time of the test; + mail relays which _will_ relay my mail back to be counted, but which haven't yet. Anyway, here are the results -- comments welcome! Out of 3751 MX hosts that we tried to use as a relay: + 269 (7%) accepted our message, but later bounced it + 1208 (32%) relayed our message OF the messages that were relayed: + 929 (76%) were from hosts named under co.nz + 33 (2%) were from hosts named under net.nz + 72 (5%) were from hosts named under govt.nz + 15 (1%) were from hosts named under ac.nz + 22 (1%) were from hosts named under school.nz + 0 (0%) were from hosts named under iwi.nz + 8 (0%) were from hosts named under gen.nz + 38 (3%) were from hosts named under org.nz + 1 (0%) were from hosts named under mil.nz I will not publish the list of MX hosts that did or did not permit relaying in this experiment. If you'd like to enquire about whether an MX host that you maintain relayed our message, please contact me directly. Methodology: 1. Zone transfers were performed for the NZ second-level domains co.nz, ac.nz, mil.nz, gen.nz, org.nz, school.nz, iwi.nz, and net.nz. 2. For every key in each of these zonefiles with an NS record, the key was extracted. A unique list of keys with NS records was generated. 3. MX records for each key were harvested from the DNS and a unique list of mail exchangers to be tested was produced. 4. A message with envelope sender jabley(a)patho.gen.nz and envelope recipient relayed(a)patho.gen.nz was sent by connecting to each relay and talking SMTP. Each message contained a random key which was stored in a local database. 5. Every time a message was received with a matching key in the body text and addressed to relayed(a)patho.gen.nz, the local database was updated indicating that the MX host in question permitted the relay. 6. All SMTP connections were made from tardis.patho.gen.nz (203.97.2.226) between 0500, Feb 5 1999 and 1400, Feb 6 1999. 7. MX hosts which specifically (intentionally) permit mail relaying from tardis.patho.gen.nz were excluded from summary reports. --------- To unsubscribe from nznog, send email to majordomo(a)list.waikato.ac.nz where the body of your message reads: unsubscribe nznog