Vipul's Razor is a distributed, collaborative, spam detection and filtering
network. Razor establishes a distributed and constantly updating catalogue
of spam in propagation. This catalogue is used by clients to filter out
known spam. On receiving a spam, a Razor Reporting Agent (run by an end-user
or a troll box) calculates and submits a 20-character unique identification
of the spam (a SHA Digest) to its closest Razor Catalogue Server. The
Catalogue Server echos this signature to other trusted servers after storing
it in its database. Prior to manual processing or transport-level reception,
Razor Filtering Agents (end-users and MTAs) check their incoming mail against
a Catalogue Server and filter out or deny transport in case of a signature
match. Catalogued spam, once identified and reported by a Reporting Agent,
can be blocked out by the rest of the Filtering Agents on the network.
bsfilter is a spam filter using Bayesian(statistical) algorithm.
- a filter which distinguishes spam and non-spam mail
- support mails written in English and Japanese language
- written in Ruby
- support 3 methods for access
-- traditional Unix-style filter. study and judge local files or pipe
-- IMAP. study and judge mails in an IMAP server. IMAP over SSL supported
-- POP proxy. run between POP server and MUA. POP over SSL supported
- distributed under GPL
FuzzyOcr is a plugin for SpamAssassin which scans image attachments for
spam keywords, using an Optical Character Recognition program.
This plugin can be used to detect spam that puts all the real spam
content in an attached image. The mail itself only random text and
random html, without any URLs or identifiable information.
It is also able to do approximate matches on words, so errors in
recognition or attempts to obfuscate the text inside the image will not
cause the detection to fail.
SpamAssassin is a mail filter which attempts to identify spam using text
analysis and several internet-based realtime blacklists.
Using its rule base, it uses a wide range of heuristic tests on mail
headers and body text to identify "spam", also known as unsolicited
Once identified, the mail can then be optionally tagged as spam for later
filtering using the user's own mail user-agent application.
Additional drop-in rule sets are available at
Junk Mail Buffering Agent is a tool for preventing delivery of email until the
sender has confirmed their address. It can be used in conjunction with a spam
filter to prevent delivery of spammy-looking email unless the sender is
confirmed as valid.
jmba is designed to be used in conjunction with a spam filter such as QSF and
the mail processor procmail. When the spam filter says it thinks an email is
spam, it can be passed to jmba. jmba will queue it and send an email to the
sender containing a key; if the sender replies, the original email is
"unfrozen" from the queue and delivered.
milter manager protects you from spam mails and virus mails effectively
with milter. milter manager has embedded Ruby interpreter to control
Tumgreyspf, an external policy checker for the postfix mail server. It can
optionally greylist and/or use spfquery to check SPF records to determine if
email should be accepted by your server.
Because of its design, legitimate e-mail is never trapped or rejected. Only
spam and viruses are caught. Since adding it to our mail server (which also uses
Spam Assassin, ClamAV, and an outsourced anti-spam system), our spam level has
dropped by an order of magnitude.
It uses the file-system as its database, no additional database is required to
Spamcalc takes a hostname or a list of hostnames and determines a dns spam
score for each hostname. This value is an indication for the spam-ness of the
hostname. The higher the score, the higher the chance that the hostname is
actually a dns spam hostname.
Hostnames that are considered dns spam are hostnames with (a part of) a
sentence in them (master.of.the.world.net), swearwords
(shittywhore.armaster.roadkill.net) and other forms of unwanted textual data
This plugin enables the scanning of incoming mail received from a POP, IMAP,
or LOCAL account using Bogofilter. It can optionally delete mail identified
as spam or save it to a designated folder. Bogofilter is a pure Bayesian
filter, therefore it has better speed performance than SpamAssassin but might
catch less spam.
relaydb is a mail header analyzer that builds a database of IP addresses either
known as legitimate senders or spammers.
relaydb doesn't itself classify mails as legitimate or spam, that decision needs
to be reached through other means. Neither does relaydb block spam itself. It
merely provides a list of IP addresses to block through other means.