alt.energy.homepower

On Mon, 27 Aug 2007 16:49:16 -0400, (PeteCresswell) wrote:

> I guess some ISPs spam filtering is better than others.
>
> The ultimate seems tb Earthlink's challenge/response system.
>
> People Who Know internet-wise despise it; but long term it looks
> to me (who knows nothing) like a solution.
>
> Short term I can see that it generates all sort of extraneous
> email issuing the challenges - aggravating the existing spam
> overload problems for mail servers. But long term, it seems
> like if everybody had it spamming would cease tb profitable and
> therefore go away.

The main problem with C/R systems is that they filter out a lot of wanted
email. Someone who is merely "inclined" (rather than "desperate") to send
you a message will send the email, get the challenge, then decide not to
bother (or simply not get the challenge because it's been flagged as spam
by an automated system, based upon the fact that thousands of
near-identical messages are sent to many different addresses).

If you want to sign up for any automated mailings (mailing lists,
email notification etc), you have to manually whitelist the sender address
(assuming that you know what it is before they try to send you email).
Someone running automated mailings isn't going to manually respond to
challenges.

Also, because of all the bogus challenges sent in response to spammers
using other people's addresses, C/R systems significantly increase the
risk that your own email address gets blacklisted for spamming.