[BUGS] Forged-sender bounce spam: how to avoid/mitigate?

[Andrew Reilly]

Aargh!  I don't know what, if anything, I'm doing wrong, but
I'm attracting an awful lot of forged-sender bounce mail at the
moment: of the 4500 or so messages in my freebsd mailing list
incoming folder, 3300 or so were this sort of spam.  They seem
to get past my bayesian spam filter (bogofilter) quite easily.
My usual inbox typically attracts several hundred of these
every day, too.  Is anyone else seeing this?  Anyone have any
effective strategies for mitigation?  I've been able to avoid
RBL systems for years, because my baysean filter has worked so
well, but this is just maddening.  I have to try *something*
else.

[Most of it seems to be to/from Russian or Korean addresses.
Maybe I've had my e-mail address harvested onto some commonly
used "sucker" list?]

It's certainly an eye-opener to see how many mail servers there
are out there that dutifully bounce e-mail, according to the
old-school rules...

Cheers,

Andrew