RE: is reverse dns required? (policy question)

[cjosephes () ibsys com]

> Quick example, though: of 6936 patterns currently in my list, if you
> just run a cut on \\ (which catches either '.' or '-' as the 
> next char,
> for the most part) you get (matches of 20 or more):
>
> count first left-hand pattern part
> ----- ----------------------------
>  1572 ^[0-9]+
>   206 ^.+
>   200 ^host[0-9]+
>   179 ^host

Exceedingly long list cut....

Just to throw in my own 2 cents:  I find it really ironic that we rely on
reverse DNS data that potentially comes from a spammer in order to determine
whether or not someone is a spammer.  It probably works for the zombies.
But in the long run, ip based filtering is quicker, since there's no DNS
check and you have a better idea of the size of the netblock you're
filtering.

I'll be a lot happier once the smtp-submission port (587) catches on.  It
will make filtering a lot simpler.