referrer-spam-blocker - Apache, Nginx, IIS, uWSGI, Caddy & Varnish blacklist + Google Analytics segments to prevent referrer spam traffic 👾

•    VCL

.htaccess is a configuration file for use on web servers running Apache. This file is usually found in the root “public_html” folder of your website. The .htaccess file uses two modules to prevent referral spam, mod_rewrite and mod_setenvif. Decide which method is most suitable with your Apache server configuration. This file is Apache 2.4 ready, where mod_authz_host got deprecated. The web.config file is located in the root directory of your Windows Server web application.

openprotect email filter

OpenProtect is an anti spam server providing spam filter and virus blocker as an email smtp gateway. Please head to http://www.openprotect.com for more information. You can get a free download at http://www.openprotect.com/anti-spam-download

Spamassasin - Intelligent Spam Filter

•    C

SpamAssassin is a mature, widely-deployed open source project that serves as a mail filter to identify Spam. SpamAssassin uses a variety of mechanisms including header and text analysis, Bayesian filtering, DNS blocklists, and collaborative filtering databases. SpamAssassin runs on a server, and filters spam before it reaches your mailbox.

DSpam - Content based Spam Filter

•    C

DSPAM is a scalable and open-source content-based spam filter designed for multi-user enterprise systems. DSPAM is an adaptive filter which means it is capable of learning and adapting to each user's email. Instead of working off of a list of rules to identify spam. DSPAM's probabilistic engine examines the content of each message and learns what type of content the user deems as spam or nonspam.

Honeypot - Simple spam prevention package for Laravel applications

•    PHP

"Honeypot" method of spam prevention is a simple and effective way to defer some of the spam bots that come to your site. This technique is based on creating an input field that should be left empty by the real users of the application but will most likely be filled out by spam bots. This package creates a hidden DIV with two fields in it, honeypot field (like "my_name") and a honeytime field - an encrypted timestamp that marks the moment when the page was served to the user. When the form containing these inputs invisible to the user is submitted to your application, a custom validator that comes with the package checks that the honeypot field is empty and also checks the time it took for the user to fill out the form. If the form was filled out too quickly (i.e. less than 5 seconds) or if there was a value put in the honeypot field, this submission is most likely from a spam bot.

SMTP Guard Filter

Spam filter for SMTP server. Check emails for spam against 9 different filters. Easy to customize and tune to your specific needs. Easy to create new filters. Eliminate 99% of spam.

bogofilter -- Fast Bayesian Spam Filter

•    Perl

Bogofilter is a mail filter that classifies mail as spam or ham (non-spam) by a statistical analysis of the message's header and content (body). The program is able to learn from the user's classifications and corrections. Bogofilter provides processing for plain text and HTML. It supports multi-part MIME messages with decoding of base64, quoted-printable, and uuencoded text and ignores attachments, such as images.

Quick Spam Filter

•    C

Quick Spam Filter is a small, fast spam filter that works by learning to recognise the words that are more likely to appear in spam than non-spam. It is intended to be used in a procmail recipe to mark email as being possible spam.

Scrollout F1 - An easy-to-use anti-spam email gateway

•    C++

Scrollout F1 is an easy to use, already adjusted email firewall (gateway) offering free anti-spam and anti-virus protection aiming to secure existing email servers, old or new, such as Microsoft Exchange, Lotus Domino, Postfix, Exim, Sendmail, Qmail and others.

Maildrop Spam Filter

Adapted a procmail spam filter for use by maildrop (used by courier mail server). Any identified spam has a header added that marks it as spam and gives a reason. Also converts mime parts of content type text/html into text/plain in suspect e-mails.

Rspamd - Fast, free and open-source spam filtering system

•    C

Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules including regular expressions, statistical analysis and custom services such as URL black lists. It supports Regular expressions filtering, SPF, DKIM, DNS black list, URL black lists, Fuzzy hashes etc.

Spam Trainer

•    CSharp

Not all email clients have Spam filtering (and training) built in. Spam Trainer provides easy (drag and drop) training from your mail client, passing messages through to your spam filter (e.g. Spambayes) via command line scripts.

SpamProbe - fast bayesian spam filter

•    C++

Fast, intelligent, automatic spam detector using Paul Graham style Bayesian analysis of word counts in spam and non-spam emails. Filtering adapts to personal tastes automatically. No manual rule creation required. Intended for use with procmail, maild

ASSP - Anti-Spam SMTP Proxy

•    Perl

ASSP is a SMTP proxy which sits between SMTP server and the MTA. It filers the spam and delivers the legtimate mails to the MTA. Its feature include Bayesian analysis, Sender Policy Framework) validation and blocking, Realtime Blackhole Listing, URL Black Listing, Multi-level attachment blocking, LDAP support, Backscatter Detection, SNMP support and lot more.

php-ext-trie-filter - php extension for spam word filter based on Double-Array Trie tree, it can detect if a spam word exists in a text message

•    C

php extension for spam word filter based on Double-Array Trie tree, it can detect if a spam word exists in a text message. PHP 5.2 or later.

Hermes Secure Email Gateway

•    C

Hermes Secure Email Gateway is a Free Open Source Email Gateway that provides Spam, Virus and Malware protection, full in-transit and at-rest email encryption as well as email archiving.

Spay - SPam BAYesian Filter Project

•    C

This project applies statistical text categorization techniques to the domain of spam mail filtering. The goal is to produce mail filtering software that can be trained to recognize spam in a particular individual's email. The statistical models produc

hosts - Extending and consolidating hosts files from several well-curated sources like adaway

•    Python

This repository consolidates several reputable hosts files, and merges them into a unified hosts file with duplicates removed. A variety of tailored hosts files are provided. The Non GitHub mirror is the link to use for some hosts file managers like Hostsman for Windows that don't work with Github download links.

nginx-badbot-blocker - Block bad, possibly even malicious web crawlers (automated bots) using Nginx

•    Shell

223 (and growing) Nginx rules to block bad bots. If you have a bizarre or complicated setup, be sure to look everything over before installing. However, for anyone with a fairly straightforward Nginx installation, this should work without any issues.

SMTP Proxy Server as spam/virus filter

•    VB

A proxy smtp server with 1. Use of user-selectable DNSRBL lists to reject mail with customised rejection messages 2. Spam trap addresses to identify dictionary attacks and other spam sources 3. White listing and blacklisting by IP addresses and domain