> > Can you imagine a valid list server sending your Imail box 5 or 10 bad > > users in one SMTP session? not very realistically > >Not a valid list server but there are broken, legitimate, mass-mailing >programs that might do so.
The non-abusive list server has its membership list. The better ones will sort the list by @recipient.domain, connect to that MX, and start hosing out the RCPT TO's. A very dirty list might have 5% bad addresses (good lists have less the 0.5%), so in 25 RCPT TO's, you'd expect 1 bad address (4% bad), maybe 2, but 5 or 10 bad is clearly way beyond what a "good faith" list server/admin would tolerate since 20% or 40% bad addresses would make the list extremely difficult to send out. >Of course, the result is the same: blacklist >them. yep >As I see it, the operative wording is "per session". yep, that's your "guard condition". Another "guard condition" for automtatic blacklisting is whether the sending ip has a PTR record. If it does, I don't black list them and/or I conditionally raise its threshold for being blacklisted. > I have seen >innocent human users repeatedly (>5 times) try to send to a non-existent >user at some domain but obviously on separate sessions. Kind of like >impatient people waiting for the elevator who keep pressing the button as >if, somehow, the elevator will take notice... > >But this is getting off-topic, no, behavior of stupid/naive mail users has to accommodated. :)) Len __________________________________________________________________ www.menandmice.com/DNS-training : DNS Training BIND8NT.MEIway.com : ISC BIND for NT4 & W2K IMGate.MEIway.com : Build free, hi-perf, anti-abuse mail gateways To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
