Evan Platt wrote:
> I looked through the FAQ and googled, so if I'm missing the
> documentation on how to do this, please let me know..
>
> I'd like to implement either tarpitting or some method of blocking
> spammers attempting dictionary attempts.

Postfix doesn't come from the factory with tarpitting in the form of
exponential response delays for blocked sites.

The more recent versions of Postfix do have the "anvil" feature, to prevent
network denial of service attacks from repeated connections. The controls for
it are smtpd_client_recipient_rate_limit and smtpd_client_connection_rate_limit.
References: "man 8 anvil" "man 5 postconf"

Postfix was designed to use 3rd party plug-ins for policy features such as you
are wanting. One configuration hook is: check_policy_service
Reference: Policy servers/libraries at: http://www.postfix.org/addon.html
Note: The word "policy" in this case does not refer to Sender Policy
Framework (SPF).

--
Greg