sendmail (Junk Mail)

[Robert Canary]

Our administrator boxes get flooded with emails from spammers who are 
still sending massive emails to address that do not exist.  Of course 
sendmail sends a response back to the from header saying the account 
dosen't exist.  However, the sendmail server is getting those responses 
bounced back to them because these are junk emails with no real return 
address.  As a result the undeliverable mail gets sent to "postmaster". 
  Thus the "postmaster" email is a hoard mess of junk email bounced replies.

How is being handled ?

--
robert