I think the performance hit and reliance on an external
connection for every email processed was at least an
equal concern.
In practice is that just not a problem? How about
a network timeout situation? How does that end up
working out? Sounds like you (Christopher) at least
have a fairly high mail volume.
-glenn
Christopher M. Iarocci wrote:
Glenn Little wrote:
Regarding the RBL checks, we just didn't want the overhead (we
process a ton of email). Also, we're a university and some of
our "customer base" is pretty against the RBL concept.
Same thing with razor and pyzor.
Maybe those are what would get us more reasonable scores,
I don't know. But for better or worse, using any of them
would be a difficult sell at this point.
-glenn
Why? If you use these things within SpamAssassin, the rule still holds
true that no one thing will make a message spam or ham. So, if a
message hits 3 seperate black lists, and that makes it spam, can your
"customer base" seriously say that 3 different black lists falsely
listed a server and it was falsely tagged as spam? I think THAT would
be the difficult sell. Using these lists alone as the sole reason to
block email definitely can be argued against, but I've found that some
lists, specifically the ones that list dynamic IPs, have little to no
false positives. Considering the amount of email I block with a single
RBL that lists dynamic IPs, I would NEVER turn it off. 6 months with
150000-200000 emails a day, and not a single complaint of a false
positive is pretty dam good. So, if you choose your RBLs wisely, using
them to block email directly with your MTA can work.
Razor, Pyzor, and DCC list emails based on human submissions (the best
spam detector in my opinion is a human). These lists are probably more
accurate because it is the actual content of the message that is
blacklisted, not the server it came from. So, Bob Legit's email even
though it comes from the same server as Joe Spammer's email, will not
get marked by one of these lists. Again, the rule holds true though, no
single one of these lists alone will cause a message to be marked spam.
Chris
