On Sun, 2011-12-11 at 18:10:34 -0500, Jim Seymour wrote: > Looking in /var/log/maillog... > > Dec 11 17:47:08 myhost postfix/smtpd[48290]: connect from > unknown[89.73.201.168] > Dec 11 17:47:10 myhost postfix/smtpd[48290]: NOQUEUE: reject: > RCPT from unknown[89.73.201.168]: 450 4.7.1 Client host > rejected: cannot find your reverse hostname, [89.73.201.168]; > from=<a...@carloerbareactifs.com> to=<nngu...@mydom.ain> > proto=ESMTP helo=<89-73-201-168.dynamic.chello.pl> > Dec 11 17:47:11 myhost postfix/smtpd[48290]: lost connection > after DATA from unknown[89.73.201.168] > Dec 11 17:47:11 myhost postfix/smtpd[48290]: disconnect from > unknown[89.73.201.168] > > This particular one occurred seven times in a row, in quick > succession.
Postfix sends a 450 response because your DNS server cannot find the client's reverse hostname; following that, the client foolishly sends DATA, to which Postfix responds with a 554. Finally, instead of gracefully QUITing, the client drops the connection. -- Sahil Tandon
