incorrect spam setups cause spool messes on forwarders
vixie at vix.com
Tue Dec 2 15:13:15 UTC 2003
> telling spammers 4xx or 5xx doesn't matter, they don't listen.
yes, but interestingly, every "smtp transport" (remote ip address who
connects to your tcp/25 service) who ignores 5XX (which you can tell
because they come back and try the same thing again over and over) is
either a spammer or the output side of a proxy (which might be hard
to detect). so it turns out that ignoring 5XX is like sending up a
flare, "blackhole me!".
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