Spamassassin Ndr

Spamassassin is typically run on a mail delivery agent so that spam can be held and not downloaded to the user.
Spamassassin: An open-source spam filtering system currently maintained by the apache software foundation, and used by many small-to-medium-size isps, online businesses, and end-users.
Spam filtering services offered by many retail isps, commercial online spam-filtering services (such as spamcop), mda-based procmail scripts, or packages like spamassassin, are all examples of on-network filtering.
Administrators can specify the tests to be used by their local spamassassin installations, can vary these tests for each user, and can even write their own tests using a basic syntax plus regular expressions.
SpamAssassin puts its results into an X-line within the message header.
While it is arithmetical in nature, spamassassin is not itself a bayesian filter, although bayesian filters can be included as spamassassin tests.

spamassassin ndr