[CentOS] please block user

Gary Stainburn wrote:
> Bad news Guys, they've just moved the emails to somewhere else and have
> started again:
<snip>

A suggestion: there should be a way to filter using *domain* AND mailhost;
that is, if emails come from a domain, and through one mailhost, then
block the domain. If many domains, and the same mailhost, only then block
the mailhost.

I've been thinking about this since yesterday, when I got back from
vacation, to hear from my manager that he had to screw with mailman,
because we were getting a lot of emails from elsewhere, subscribing to one
or more of our lists... and having the target be one of three gmail
accounts - a DDoS against them (and we assume that they're doing it to a
lot of other places).

Anyway, given the number of times I've been blocked by nixspam (which I
found is run by IX, a German IT mag, and that they don't answer emails to
*them*, either), I've been trying to think of a *reasonable* way to block
that doesn't do collective punishment to the many domains of a huge
hosting provider, and that's my best thought so far.

         mark