"Tim Hunter" <ti...@brokenbits.com> wrote:
and at some point during the trip, my home ISP kindly reconfigured
their network and all of my hosts were given new IP addresses without
me knowing what they were.
Sounds like you need a Dynamic DNS service. Even if your addresses are
allegedly static: if you don't trust the ISP not to mung them, in effect
they are dynamic.
I don't like to accept and delete because that way there is no feedback
that tells the spammer it was simply rejected outright.
Even worse: there is no feedback for a non-spammer (false positive).
Perhaps I'm delusional, but I'm convinced that my total rate of incoming
SPAM has lessened due to this reject-at-the-front-door policy.)
It's a good policy, but it's better if you use it consistently. When a
message arrives via your work MX, the front door is your work MX, and
it would be better to reject the message at the front door.
My suggestion for you: configure your home milter to accept every message
that arrives from your work MX. If this gets you too much spam, use
more aggressive blocking on the work MX.
Anyway, I think I might have to take Sam's suggestion and drop the
secondary MX'ing. The same scenario occurs when mail comes in that
generates 550 User unknowns as well (i.e., usually mis-targeted SPAM
that uses a bad address).
This is a well known, classic problem. The classic solution is to keep
the secondary MX informed about your valid user list, so it can generate
those 550s directly.
What baffles me however is why there's been this sudden increase in these
DSNs since I moved my Courier server [...] a few tweaks to the aliases.
Surely I should've been getting them all along; not just now?
Deliberately sending to a secondary MX, even when the primary MX is
available, is a well known spammer trick. Possibly one of the spammers
who has you on his victim list recently decided to add that trick to
his bag, and the timing is just a coincidence.