lame reverse DNS?

From: Michael Butler <imb_at_protected-networks.net>
Date: Mon, 17 Feb 2020 11:45:46 -0500
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)

	imb
Received on Mon Feb 17 2020 - 15:56:26 UTC

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