From: Gordon J. Holtslander (holtsg@duke.usask.ca)
Date: 02/21/03-01:48:11 PM Z
Hi:
A critique of spamcop os here: http://jhoward.fastmail.fm/spamcop.html
Everything thats wrong with spamcop ...
SpamCop is using the 1st style of filtering. It blocking messages because
they are coming from a particular computer. It does not read the message
to check for spam content
SpamCop uses a blacklist - It will reject message from any computer on the
blacklist.
A computer can be added to the blacklist by someone reporting to have
recieved spam from this computer.
If there is a recent report of spam from a computer it will be
blacklisted. After a while, if there are no complaints the computer will
be unblacklisted.
So if sask.usask.ca is currently on the blacklist Katherine's email from
the list gets tossed in the garbage. When it comes off the list she gets
email, but she will NEVER recieve the email that was sent while
sask.usask.ca is blacklisted
This also depends on the ISP maintaining updated information - likely
needs to be updated every 4 hours.
The problem is that occasionally valid email gets reported as spam
Quoting above site:
-----------
A SpamCop report occurs when a SpamCop notification system user reports a
message as spam, and SpamCop's analysis results in it being connected with
a particular email server. At FastMail.FM we have seen the following
result in SpamCop reports
Genuine spam is correctly connected with the correct sending server.
Genuine spam is received by a user, who forwards it to another email
provider (e.g. due to an automatic rule they have set up) or moves it with
their email client manually, and is then reported from the final location.
This can result in their own email provider getting listed because that
looks like the "spam source", because that is the server through which it
was forwarded.
A virus results in an email being sent, which is incorrectly reported as
spam.
A SpamCop notification user sends someone a message which the recipient
bounces (e.g. they are rejecting emails from that sender automatically),
and the SpamCop user reports the bounce notification.
-------------
>From the error message posted on spamcops site it appears that someone was
forwarded, or recieved through a virus, spam that had originally been sent
to a sask.usask.ca address. They filed a spamcop report on this,
resulting in sask.usask.ca being blacklisted.
This means that any ISP using SpamCop will toss all list messages in the
garbage when this occurs.
Its up to list suscribers to deal with their ISP's about this. I can't do
anything about it.
Gord
On Fri, 21 Feb 2003, Eric Maquiling wrote:
> On 02/21 10:05, Katharine Thayer wrote:
> > On the other hand, an ISP-level filter that blocks messages with the
> > subject line "Aqua Regia" might at some times be a useful feature.
>
> Sorry for being REALLY OT here but 2 things can happen at the ISP
> level. Think of them as 2 doors:
>
> 1st door
> email comes in
> email servers ask "what IP address did you come from?"
> email server looks up the IP address
> lookup says "that IP address routinely sends SPAM"
> email server closes the door on that email
> next mail
> lookup says "that IP address is good"
> email server forwards the mail to:
> 2nd door
> another serivce
> checks for the entire email for anything that might be
> considered as spam
> checks good
> email goes to recipeient
> checks bad, words like "click here now!" or "increase your ***"
> email gets rejected.
>
> This concludes our basic email server lesson for today.
>
> (Thought I might contribute to something I actually know something
> about)
>
> You guys are super cool printmakers.
>
> --
> Eric
>
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Gordon J. Holtslander Dept. of Biology
holtsg@duke.usask.ca 112 Science Place
http://duke.usask.ca/~holtsg University of Saskatchewan
Tel (306) 966-4433 Saskatoon, Saskatchewan
Fax (306) 966-4461 Canada S7N 5E2
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