The most any filter for non-specific addresses should do is either bounce
or delete mail [exception snipped].
Even bouncing may be too much. I've been doing that with the idea that
the more hassle I give the spammers, the better. But at least 20% *
double bounce when based on procmail/formail header parsing, and if based
on EXITCODE = <number> my sysadmin has to delete an advisory message that
mail to me bounced.
*Surprisingly small considering that most spam is forged. How many
innocents have gotten my bounces?