On 9/27/2020 8:33 AM, Keith Moore wrote:
On 9/27/20 11:04 AM, John R Levine wrote:
Anything that comes from a dynamic or NAT pool is invariably spam from
No, because nobody is looking that closely. It's basically just
prejudice that assumes that "legitimate" senders have static IP
addresses, delegation of the corresponding zone in in-addr.arpa, and
the knowledge to populate the PTR records.
John L. has been correctly summarizing what members of M3AAWG have been
quite consistent about, for many years. It is part of the reason that
running a legitimate mail server on the open Internet, these days,
requires a significant amount of knowledge about the rather elaborate
set of expected configuration and procedure.
Properly registering the domain name and the IP address, forward and
backwards, has been one of the more basic and practical requirements for
at least 10 years, that I know of, but probably a lot longer.
As for 'prejudice', I encourage folk to spend some time around the
anti-abuse industry and learn more about how it operates, since it takes
a 95% spam level for incoming mail and brings in down to a tiny percent.
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