On 9/13/2006 16:35, A.Omer Koker wrote:
> 
> Or you might use a service that asks for the sender to confirm their email
> authenticity by clicking on a link and adding them to your whitelist.  
> Since the message specifically asks the user to click a link (http) there is
> no valid (or another /dev/null) return email adr catching any loops or error
> messages.   I ran across this service some time ago but misplaced the link
> so if someone else knows what im talking about PLEASE send links on
> company/applications that does this.  
> 

Challenge/response is just another form of back-scatter which will get you
blacklisted by some sites.

-- 
Paul Russell, Senior Systems Administrator
OIT Messaging Services Team
University of Notre Dame
[log in to unmask]