Mark Delany wrote: >> Do you mean the server's side of the connection will have buffer >> data in it? That would mean the client sent DATA<CR><LF> followed >> by header/body information, possibly even in the same packet, >> without waiting for the reply from DATA. The server could drop the >> connection > > I haven't been watching lately, but at some point a popular bot > technique was to send the whole transaction without looking at the > responses. After all, what do they care? > > It was popular enough to generate the "greet_pause" feature in > sendmail - as you must know. I don't know whether "greet_pause"-type > detection is so wide-spread now that spammers have moved away from > doing it, but I'll bet a lot still don't care and just blast away. >
Yup. Bad clients attempting to behave as a RFC 1854 PIPELINING client still occurs out there regardless if the SMTP server doesn't even advertise Pipelining EHLO response support. They are blasting away at random sites to see what sticks to get their foot the door which is basically step one - message acception. They really don't care if you reject/discard before or afterwards. Furthermore, I venture that most mom and pop spammers, doesn't invest too much money in getting SMTP clients compliant with SMTP. In any case, non-PIPELINING servers should count consecutive bad command errors and drop the session. Pauses just delays the session completion and can affect incoming worker queue designs. == HLS _______________________________________________ NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html
