grep filters to block open relay

[John Jolet]

>
> They are not blocking reporting addresses, they are blocking email  
> addresses in the format used to test an open relay.  For instance,  
> to block user%ibm.com at sun.com they might block anything with a %  
> character followed by an @ character, with any character allowed in  
> the three other spots.  I don't know if this example is accurate,  
> but you get the general idea.
>
> hermit921
>
sure, but it's going to be just as ineffective, and just as legally  
lethal in the long run....