On Sun, Jul 12, 2009 at 11:55:36AM +0200, Ole Tange wrote: > 2009/7/12 Keld Jørn Simonsen <k...@dkuug.dk>: > > > from the /var/log/mail/info file: > > > > Jul 12 09:12:48 rap postfix/smtpd[6597]: NOQUEUE: reject: RCPT from > > unknown[92.45.179.70]: 450 4.7.1 Client host rejected: cannot find your > > reverse hostname , [92.45.179.70]; from=<eononagenar...@ajsquare.com> > > to=<k...@rap.rap.dk> proto=ESMTP helo=<asy70.asy179.tellcom.com.tr> > > > > I then used: > > host 92.45.179.70 > > > > Which gave: > > > > 70.179.45.92.in-addr.arpa domain name pointer asy70.asy179.tellcom.com.tr > > > > And this means that there is a PTR RR. > > > > Can it be something about postfix not set up to do reverse name lookups? > > Notice how you get a 4xx error code. It may simply be your nameserver > did not get an answer quickly enough.
you mean by debugging via tcpdump or the like? > > If you see no reverse lookups succeeding at all, then it may be your > resolv.conf that does something weird. The host command was done on the same machine. and responses seem fast enough. Anyway asy70.asy179.tellcom.com.tr is a NXdomain. So maybe postfix tries to look up the name it got from the PTR. best regards keld