[CLUE-Tech] reverse DNS

[David Anselmi]

Charles Oriez wrote:
[...]
> as an anti-spam tool, rejecting traffic from servers without valid RDNS 
> rejects a significant percentage of spam.  spam sent through trojaned  
> machines in particular tend not to have valid rdns

Do you have false positive and false negative numbers for that 
technique?  Preferrably independent of other filters.

Do you reject (based on RDNS) at SMTP time or after?

Dave