Jeff Franks wrote:

MAPS=Mail Abuse Prevention System
RBL=Real-time Blackhole List

Both of these are "blacklists" that many mailservers use to try to prevent
spamming.

Up to here, you're right.

RBL (or "DNSRBL" or some variation) has come to be the generic label for the
technology used by MAPS and many other "providers". These providers
provide databases of "problem" IP addresses.

How "problem" is defined varies from list to list. Some list open relays.
Others list those that have sent spam in the past. Others list IPs
allocated to DSL or cable users. And so on.

An ISP - or, in many cases now, individual users - can choose one or more of
these lists to use in filtering their email. They can choose to block mail
from listed addresses outright for one list, or to block mail from
addresses listed on some number of lists, or whatever. Antispam software
is becoming quite flexible.

RBLs kind of act like a "consumer reports" of email transmission. Users
choose which of these lists to trust, and how far. However, there are
plenty of other tools beyond just RBLs. A lot of antispam software
provides some combination of tools, with RBLs being just one.

Most of these tools also provide for whitelists, which means that people can
deliberately "permit" your email, even if it would otherwise be rejected.
However, these can be easily abused themselves as anyone can forge email to
appear to be from anyone else's address.

What happens is some mailservers (probably some at mediacom
were
like this) aren't correctly setup. If the server is an "open relay"
server, then it allows outside mailers to use the server to bounce spam
off of. Meaning that I could use Mediacom's servers to send out millions
of spam messages even though I'm not a mediacom subscriber.


This isn't quite correct. Your description of "open relay" is correct, but
MAPS lists more than just this. In fact, I'm not sure that MAPS lists open
relays at all anymore; there are other lists which do this.

MAPS is just one of many list providers. However, they're one of the most
responsive to listed ISPs. Your ISP should contact them, and - together -
they can resolve the problem. Actually, it sounds like this is in progress
already.

I am saddened that you've been adversely impacted by the tools being used to
fight spammers. I remember a much simpler time, when "open relay" was
considered the polite way to configure a mail server.

Remember that spammers exist because someone is buying. That tells us the
best way to kill them off: get people to stop buying from spammers. Until
then, though, or until some other solution kills them off, I'm afraid that
we must all live with the mess those ... people ... have made of email.

- Andrew