Re: [Dovecot] is reverse dns down ?
Quoting Stan Hoeppner s...@hardwarefreak.com: On 5/2/2011 6:30 AM, Voytek Eymont wrote: # host 194.89.34.45 Host 45.34.89.194.in-addr.arpa. not found: 3(NXDOMAIN) ~$ host 194.89.34.45 45.34.89.194.in-addr.arpa domain name pointer mkentta.iki.fi. ~$ prdns.pl 194.89.34.45/32 194.89.34.45: mkentta.iki.fi ~$ rdns-tool.pl 194.89.34.45/32 using mask 32 194.89.34.45: mkentta.iki.fi Looks like there's a DNS issue on your end. Try flushing your cache. For obvious reasons Postfix returns a 450 in this case, so the list server will attempt delivery for a few days. If you don't run your own resolver on your Postfix MX I suggest you do so. I use PowerDNS recursor on my MX MTAs. Works great. Setup takes less than 5 minutes. Caching is in memory only, not disk, so a restart clears everything. -- Stan got a mail from sonera today which says it's fixed. Helga Helga Mayer Universität Hohenheim Kommunikations-, Informations- und Medienzentrum (630) IT-Dienste | Mail Schloss-Westhof-Süd | 70599 Stuttgart Tel.: +49 711 459-22838 | Fax: +49 711 459-23449 https://kim.uni-hohenheim.de
[Dovecot] is reverse dns down ?
Hi guys, is that a genuine email from the list, I'm getting it rejected as it's missing reverse hostname: May 2 21:21:41 postfix/smtpd[18033]: NOQUEUE: reject: RCPT from unknown[194.89.34.45]: 450 4.7.1 Client host rejected: cannot find your reverse hostname, [194.89.34.45]; from=dovecot-boun...@dovecot.org to=voy...@sbt.net.au proto=ESMTP helo=mkentta.iki.fi # host mkentta.iki.fi mkentta.iki.fi has address 194.89.34.45 mkentta.iki.fi mail is handled by 10 mkentta.iki.fi. mkentta.iki.fi mail is handled by 100 smtp.menturagroup.com. # host 194.89.34.45 Host 45.34.89.194.in-addr.arpa. not found: 3(NXDOMAIN) -- Voytek
Re: [Dovecot] is reverse dns down ?
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Re: [Dovecot] is reverse dns down ?
On 5/2/2011 6:30 AM, Voytek Eymont wrote: # host 194.89.34.45 Host 45.34.89.194.in-addr.arpa. not found: 3(NXDOMAIN) ~$ host 194.89.34.45 45.34.89.194.in-addr.arpa domain name pointer mkentta.iki.fi. ~$ prdns.pl 194.89.34.45/32 194.89.34.45: mkentta.iki.fi ~$ rdns-tool.pl 194.89.34.45/32 using mask 32 194.89.34.45: mkentta.iki.fi Looks like there's a DNS issue on your end. Try flushing your cache. For obvious reasons Postfix returns a 450 in this case, so the list server will attempt delivery for a few days. If you don't run your own resolver on your Postfix MX I suggest you do so. I use PowerDNS recursor on my MX MTAs. Works great. Setup takes less than 5 minutes. Caching is in memory only, not disk, so a restart clears everything. -- Stan
Re: [Dovecot] is reverse dns down ?
On Mon, May 02, 2011 at 10:30:44PM +1100, Voytek Eymont wrote: Hi guys, is that a genuine email from the list, I'm getting it rejected as it's missing reverse hostname: May 2 21:21:41 postfix/smtpd[18033]: NOQUEUE: reject: RCPT from unknown[194.89.34.45]: 450 4.7.1 Client host rejected: cannot find your reverse hostname, [194.89.34.45]; from=dovecot-boun...@dovecot.org to=voy...@sbt.net.au proto=ESMTP helo=mkentta.iki.fi # host mkentta.iki.fi mkentta.iki.fi has address 194.89.34.45 mkentta.iki.fi mail is handled by 10 mkentta.iki.fi. mkentta.iki.fi mail is handled by 100 smtp.menturagroup.com. # host 194.89.34.45 Host 45.34.89.194.in-addr.arpa. not found: 3(NXDOMAIN) We discussed this the other day under Timo's thread about dovecot.org. It seems that ns.ripe.net., one of the NS hosts for 89.194.in-addr.arpa., is not returning the PTR for 45.34.89.194.in-addr.arpa. AFAICS the other NS hosts seem to be working fine, but if your resolver was unlucky enough to hit ns.ripe.net., you have a host with no PTR. It's like Russian roulette with rDNS. I suspect it might be a casualty of DNSSEC, but I get the same noerror response when querying with +dnssec and +nodnssec. At this point those who use the normally safe and reasonable reject_unknown_reverse_client_hostname restriction should consider whitelisting mkentta.iki.fi[194.89.34.45] in the MTA. And Timo needs to scream louder at the ISP. ;) -- Offlist mail to this address is discarded unless /dev/rob0 or not-spam is in Subject: header
