nanog mailing list archives

Re: Spamhaus...


From: Michelle Sullivan <matthew () sorbs net>
Date: Sat, 20 Feb 2010 18:31:24 +0100

Scott Howard wrote:
On Fri, Feb 19, 2010 at 5:20 PM, William Herrin <bill () herrin us> wrote:
  
On Fri, Feb 19, 2010 at 3:30 PM, Rich Kulawiec <rsk () gsp org> wrote:
    
Barracuda's engineers apparently think
that using SPF stops backscatter -- and it most emphatically does not.

Reject gooooood, bounce baaaaaaad. [1]
      
Whine all you want about backscatter but until you propose a
comprehensive solution that's still reasonably compatible with RFC
2821's section 3.7 you're just talking trash.
    

In the case of Barracuda's long history of Backscatter the solution is
simple, and is implemented by most other mail vendors - it's called
"Don't accept incoming mail to an invalid recipient".

Barracudas used to have no way of doing address validation for
incoming mail, so they would accept it and then bounce it when the
next hop (eg, the Exchange server) rejected the recipient address.
They finally fixed this a few years ago, and can not integrate with
LDAP (and possibly others) for address validation. Of course, it's
still down to the admin to implement it...

  

Actually they do (did?), as they run postfix, they should be
configurable to use LDAP and a whole host of other methods.


Michelle


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