What Can I Do About All This spam? Part 2

Read Part 1 of this series.

In addition to running their own spam filter, your ISP also has a couple more anti-spam tools in his toolbox. These two tools are ones that they can use to prevent the receipt of email, based on the email server where the email originated.

First of these has been around for several years — the RBL — the RealTime Black List. This spam control plan uses the reports of individual users, like you and me, to identify spam. If we forward complete emails, including the full headers, to the RBL coordinator, they can automatically scan them and compile realtime statistics.

When a particular mailserver has been reported frequently enough — say 50 times in the last 2 hours — the RBL system server will add that mailserver to the RealTime Black List it maintains.

The meat of this approach is that RBL users check emails against the RBL — and refuse any from servers that are on the RBL they use. This is one of the ways that the Internet email system is not reliable. If a mailserver refuses delivery of a message, you probably will not get notified and the planned recipient won’t either.

After a certain time, based on the RBL maintainer’s settings, blocked mailservers will drop off the list. Until the next time….

[Read Part 1 and Part 3 of this series]

[Read more about spam filters.]