I disagree with that. At least for us, I analyzed for a
month and didn't
have a false positive, and I NEVER have complaints after
using Zen.
(previously sbl-xbl) Spamhaus being blocked at the MTA
level. That even
addresses the "bring to the attention of
SomeCompany" because the user
gets an informative bounce and can follow up appropriately.
Accepting the
mail, then silently discarding based on an RBL is a WHOLE
'nother story.
That's just one tool in a mail admin's arsenal. Greylisting
and
recipient validation are others, and ALL of them are
necessary in one form
or another.
--
Rick Zeman
Manager of Information Technology
Melwood Horticultural Training Center
301.599.4574 - HelpDesk
301.599.4560 - MyDesk
http://www.melwood.org
>>> "Todd" <todd smart-mail.net>
11/8/2007 9:04 AM >>>
There are plenty of ways to block at the MTA without using
RBLs,
Greylisting and Relay_recipient maps are two good ones.
Relay
recipients
has cut down the load on our server tremendously and will
Never have a
false
positive.
We never block at the MTA. I see false positives all the
time from ZEN
and
other RBLs. Most of the time the simple fact of the matter
is the
SomeCompnay chose the wrong ISP to host with and the ISP is
being
blocked.
Yes SomeCompany should get a better service provider.
Unless someone
brings
it to the attention of SomeCompany then they may never know.
If we blocked on any single RBL I would be getting calls all
day long.
That's the whole point of a weight system like
Spamassassin.
Todd
_____
From: maia-users-bouncesrenaissoft.com
[mailto:maia-users-bouncesrenaissoft.com] On Behalf
Of Adam Ellsworth
Sent: Monday, November 05, 2007 1:39 PM
To: maia-usersrenaissoft.com
Subject: [Maia-users] Use RBLs in MTA or Maia?
Hello,
I'm revisiting/tweaking my Maia setup (going on a couple
years I
believe!)
and I'm still divided on proper implementation of RBLs. I've
simply read
too
many threads and gotten conflicting opinions, both of which
I agree
with...
looking for advice:
+ On the one hand, using RBLs (and SURBL?) at the MTA level
is much less
processor-intensive and rejects the mail at the SMTP
conversation level.
However, it's black and white, not real configurable and
perhaps more
prone
to false-positives.
+ On the other hand, letting Spamassassin do all the
checking seems to
be
very reliable from a false-positive standpoint, though
perhaps more
resource-intensive. It works very well for me - however, my
Maia queues
get
unmanageably large quickly; many users easily get 100s of
spams per day,
and
they're just not paying attention to the daily digests or
logging into
the
queue interface unless they already feel they're missing a
message. I
know
this impacts bayes training as well, but "forcing"
users to log into Maia
is
not an option for me... (of course some are happily using it
already.)
I posed a similar question a year or so ago and was told to
look into
blocking more at the MTA level... but other threads here
contradicted
that
advice. I recall reading at some point about implementing a
cut-off
score
where mail is unquestionably considered spam and not
quarantined. Is
that
considered a best-compromise solution now, or no?
I hope not to be off-topic or create a war against two
reasonable
methodologies... I just really need some feedback!
Thank you,
Adam Ellsworth
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