Barracuda Networks Spam Firewall

Todd Vierling tv at
Tue May 18 22:49:34 UTC 2004

On Tue, 18 May 2004 Valdis.Kletnieks at wrote:

: > Don't know about hotmail, but AOL is working on this.  You might want to
: > check out that SPAM-L list, if this is something you are interested in.
: Other than knowing that it's a good idea

s/a good idea/an emerging requirement/
(and for one definition of the idea, s/a good idea/a soon-to-be RFC "MUST"/)

: if you can do it,

s/can do it/wish to send mail, or at least DSNs, to most of the 'net soon/

: but sometimes not doable with the resources at hand,


Those of us under a deluge of virus bounce spew just don't care anymore.
If you don't reject at SMTP time, you're now a major part of the problem.
(As a straw example, I happen to block, on a personal 12 user domain, almost
20k bounce spew attempts per day.  That's simply untenable anymore.)

: > Once AOL starts doing it -- you can bet they will be one of the ones
: > blocking on it.
: That's going to pretty much torpedo the concept of secondary MX's.

And what's the gain of secondary MX's that don't have access to a valid
address list?  Ever since the advent of globally deployed, permanently
connected sending MX's, offsite secondary MX machines have become moot.
SMTP mandates that a missed connection is equivalent to a 4xx error, in that
the sender is to retry delivery later.  That obviates any need for an
offsite secondary MX in today's world.

Unauditable SMTP transport -- that is, SMTP where neither the sender nor
recipient values are verifiable -- is no longer a workable solution.  The
problems with that model are reaching critical mass, and if you don't think
it's a problem now, just trust me; you'll be a believer soon enough.

-- Todd Vierling <tv at> <tv at>

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