Maybe it's just me, but I'll take the evidence presented by someone
who has access to the operational statistics for a mail system
that services 10s of millions of end users and handles thousands of
outsourced email setups over someone like myself who runs
a tiny little setup any day.
While large scale is important, small scale setups must not be sacrificed
along the way. We must not create a system where a small cartel of players
hold the keys to 'interoperability' at the deployment level. Current
filtering practice creates way too many false positives already because the
large organizations can't afford to bother with identifying the source. My
lowly server just handles my wife, myself, and my daughter's business, and
way too often I hear complaints about bounces because largeispmailer.com is
refusing to accept mail from an insignificant non-member-of-the-club server.
By no means do I claim enough knowledge about mail services to offer
anything more than the viewpoint of an amateur trying to run a small server.
I would agree with the comments along the way that the current
state-of-the-art is way too hard, and I am sure my configuration is not
correct or complete because I get mail from the process every few hours
stating -- error: gpg required but not found! yet every time I try to
resolve that I can't figure out what is wrong or if a symbolic link is
missing. Even with help from example configs at jck & psg, it took a fair
amount of time and experimentation to cut over from the previous mta that
was being crushed by the spam load. Life is better now, and as of a few
hours ago mail from the ietf list is flowing over IPv6, but I know the MX
record still needs work because the IPv6 path is being locally redirected.
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