Barracuda Networks Spam Firewall

Tue May 18 20:57:56 UTC 2004

On Tue, 18 May 2004 16:13:20 EDT, Todd Vierling said:
> On Tue, 18 May 2004 Valdis.Kletnieks at vt.edu wrote:
> 
> : Yes, it *would* be nice if everybody in the world was able to DTRT on
> : their outward-facing gateway and send back an immediate 550 on a RCPT TO:
> : in order to stop stuff right up front.  However, this implies getting
> : buy-in and resources of all the appropriate people.
> 
> Blocking outbound mail from such entities is a pretty good way to get
> buy-in.  (Yes, there's a DNSBL in work to enumerate such systems.)

When it gets built, will it list AOL.COM for not rejecting at the original RCPT
TO?  Or Hotmail.com? (Consider the following 2 pieces of mail - mail comes in
from someplace with a From: @aol.com, our Listserv tries to process the command
(which was actually spam, but it's hard to tell that until you try to handle
it), and send the response back... notice that AOL didn't 550 my mail, but
accepted and bounced it. Similarly for the hotmail.com mail - the spam comes
in, and they accept-and-bounce our response rather than 550 it (although to be fair, they
usually DO manage to 550 this stuff).

Yes, it's generally a good idea - but not one that everybody can carry out all the time.

You don't like it, take it up with the AOL and Hotmail guys, not me, OK? :)

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