Fight Image Spam With FuzzyOCR And SpamAssassin On Debian/Ubuntu

This tutorial describes how to scan emails for image spam with FuzzyOCR. FuzzyOCR is a plugin for SpamAssassin which is aimed at unsolicited bulk mail containing images as the main content carrier. Using different methods, it analyzes the content and properties of images to distinguish between normal mails (ham) and spam mails. FuzzyOCR tries to keep the system load low by scanning only mails that have not already been categorized as spam by SpamAssassin, thus avoiding unnecessary work.

Virtual Users With Postfix, PostfixAdmin, Courier, Mailscanner, ClamAV On CentOS

In this how to I will explain how to setup a Postfix virtual mailserver with Courier-IMAP, Maildrop and Postfix Admin GUI. We will secure our mailserver with Mailscanner and Clamav as anti-virus and Spamassassin as anti-spam.

How To Automatically Scan Uploaded Files For Viruses With php-clamavlib

This guide describes how you can automatically scan files uploaded by users through a web form on your server using PHP and ClamAV. That way you can make sure that your upload form will not be abused to distribute malware. To glue PHP and ClamAV, we install the package php5-clamavlib/php4-clamavlib which is rather undocumented at this time. That package is available for Debian Etch and Sid and also for Ubuntu Dapper Drake and Edgy Eft, so make sure you use one of these platforms.

Set Up Ubuntu-Server 6.06 LTS As A Firewall/Gateway For Your Small Business Environment 

This tutorial shows how to set up a Ubuntu 6.06 LTS server ("Dapper Drake") as a firewall and gateway for small/medium networks. The article covers the installation/configuration of services such as Shorewall, NAT, caching nameserver, DHCP server, VPN server, Webmin, Munin, Apache, Squirrelmail, Postfix, Courier IMAP and POP3, SpamAssassin, ClamAV, and many more.

Postfix with dkfilter (DomainKeys Implementation)

DomainKeys is an anti-spam software application in development at Yahoo that uses a form of public key cryptography to authenticate the sender's domain. dkfilter is an SMTP-proxy designed for Postfix. It implements DomainKeys message signing and verification. It comprises two separate filters, an "outbound" filter for signing outgoing email on port 587, and an "inbound" filter for verifying signatures of incoming email on port 25. This document is to describe step by step how to install dkfilter for postfix to deploy domainkeys signing and verification.

Set Up Ubuntu-Server 6.10 As A Firewall/Gateway For Your Small Business Environment 

This tutorial shows how to set up a Ubuntu 6.10 server ("Edgy Eft") as a firewall and gateway for small/medium networks. The article covers the installation/configuration of services such as Shorewall, NAT, caching nameserver, DHCP server, VPN server, Webmin, Munin, Apache, Squirrelmail, Postfix, Courier IMAP and POP3, SpamAssassin, ClamAV, and many more.

SIEVE Language for Mail Filtering Quick Guide

SIEVE is a language created and used for mail filtering that broadens the filtering options generally provided by mail servers or Antispam/Antivirus applications. They work basically by comparing different keys using different comparators and comparison methods, against headers of a mail message. Based on the result of the comparison, you can apply different actions to the corresponding mail message, i.e. reject, discard, redirect, etc.

Enhance Your Mail Server With ASSP (Anti-Spam SMTP Proxy) 

ASSP stands for Anti-Spam SMTP Proxy. The ASSP server project is an Open Source platform-independent transparent SMTP proxy server that leverages numerous methodologies and technologies to both rigidly and adaptively identify spam. In short ASSP is the most kickass solution that is both free and works great. It reduced spam to an absurd minimum for me.

How to Build an Effective Mail Server Defense 

When speaking of mail server-related security, one tends to limit the issue to message applied security measures, and even more to Antivirus and Antispam protection. This is however only one stage in the more complex process of securing your server. This article aims at identifying and explaining all security layers, highly important when choosing a certain mail server and consequently when configuring and using it.

Virtual Users And Domains With Postfix, Courier And MySQL (Fedora Core 5)

This document describes how to install a mail server based on Postfix that is based on virtual users and domains, i.e. users and domains that are in a MySQL database. I'll also demonstrate the installation and configuration of Courier (Courier-POP3, Courier-IMAP), so that Courier can authenticate against the same MySQL database Postfix uses. In addition to that, this tutorial covers the installation of Amavisd, SpamAssassin and ClamAV so that emails will be scanned for spam and viruses.