[Dovecot] [ot] spam (was: Re: Big sites using Dovecot)

[Joshua Goodall]

On Tue, Sep 26, 2006 at 12:29:08PM -0500, /dev/rob0 wrote:
> Furthermore, users rarely understand how mail works. They think that 
> sender addresses really mean something. You got spam from some sender 
> address, so you should blacklist that address? Well duh, it probably 
> wasn't really that sender. Maybe you just blocked a real person, an 
> innocent victim of spammers.

Here's why we have white/blacklists at ISPs at all.

Whitelisting at ISPs is usually provided for users who receive mail
from broken automated systems that trip over heuristic spam-detection
filters (i.e. spamassassin and co).  Telco Fax/SMS gateways are a
typical culprit, and badly coded feedback forms at websites.

Blacklisting at ISPs is usually provided for people to block spew.
It is a mistake to provide it alongside anti-spam controls.

Both are cheap hack solutions, but it is never worth an ISP's time
coming up with a sound and correct solution (usually - fix an
external, customer 3rd party source) for what is commonly an isolated
case.  So, these imperfect but generic tools suffice.

JG