lame reverse DNS?

[Herbert J. Skuhra]

On Mon, 17 Feb 2020 17:45:46 +0100, Michael Butler wrote:
> 
> Seems there's an issue with freebsd.org's reverse DNS resulting in
> refused email, e.g.
> 
> Feb 17 08:58:54 mail postfix/smtpd[41811]: NOQUEUE: reject: RCPT from
> unknown[2610:1c1:1:606c::19:2]: 550 5.7.25 Client host rejected: cannot
> find your hostname, [2610:1c1:1:606c::19:2];
> from=<owner-freebsd-ports at freebsd.org> to=<imb at protected-networks.net>
> proto=ESMTP helo=<mx2.freebsd.org>
> Feb 17 10:55:52 mail postfix/smtpd[82117]: NOQUEUE: reject: RCPT from
> unknown[96.47.72.81]: 550 5.7.25 Client host rejected: cannot find your
> hostname, [96.47.72.81]; from=<owner-freebsd-ports at freebsd.org>
> to=<imb at protected-networks.net> proto=ESMTP helo=<mx2.freebsd.org>
> Feb 17 11:11:15 mail postfix/smtpd[83299]: NOQUEUE: reject: RCPT from
> unknown[96.47.72.81]: 550 5.7.25 Client host rejected: cannot find your
> hostname, [96.47.72.81]; from=<owner-freebsd-ports at freebsd.org>
> to=<imb at protected-networks.net> proto=ESMTP helo=<mx2.freebsd.org>
> 
> Looking more closely ..
> 
> /home/imb> host 2610:1c1:1:606c::19:2
> Host
> 2.0.0.0.9.1.0.0.0.0.0.0.0.0.0.0.c.6.0.6.1.0.0.0.1.c.1.0.0.1.6.2.ip6.arpa
> not found: 2(SERVFAIL)
> /home/imb> host 96.47.72.81
> Host 81.72.47.96.in-addr.arpa not found: 2(SERVFAIL)

The problem has been resolved but I still sometimes see "connect from
unknown[2610:1c1:1:606c::19:2]" in the maillog (today: 6 of 131
connections). Local unbound issue?

--
Herbert