@ilja @rysiek There are IPv6 only blacklists (I've complained on masto before about the bad interaction of OVH and spamhaus), but google does not block all ipv6 mail. A quick check of the logs suggests it's about 50/50 from one mailing list server to gmail. It could also be the case the less people have IPv6 reverse DNS set up, which would cause not just gmail but most smtp servers to block.
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