Email is one of the primary communication channels among users. The Radicati Group is an organisation which publishes quantitative and qualitative research on business and consumer usage for email, instant messaging, social networking, wireless email, and unified communications. Their research estimates that the number of email accounts in the world is around 3 billion, and growing at a rate of 7% each year. Corporate users send and receive about 105 email messages per day, with 19% of email messages being identified as spam despite the use of spam filters.

The cost of spam is frightening, estimated to be approximately $50 billion each year. The tide of the daily spam is a continual thorn in the side for both providers and users. Spam is a waste of valuable network bandwidth, disk space and takes up users’ valuable time to declutter their mailboxes. Many spam messages contain URLs to a dubious website or websites, peddling fake pharmaceutical products, replicas, enhancers, or gambling. Alternatively, the URLs may be phishing attacks, for example taking an unwitting victim to a site which seeks to steal private information such as bank account login data.

There are a number of techniques that help fight the tide of spam. These include whitelisting, spam buckets, bayesian filtering, fuzzy logic techniques, and attachment scanning.

To provide an insight into the quality of software that is available, we have compiled a list of 5 proficient open source Linux anti-spam tools. Each application warrants our highest recommendation.

Now, let’s explore the 5 email tools at hand. For each title we have compiled its own portal page, a full description with an in-depth analysis of its features, together with links to relevant resources and reviews.

Anti-Spam Tools Scrollout F1 Highly configurable email gateway for multiple domains and servers ASSP Perl based transparent SMTP proxy server SpamAssassin Perl-based spam filter using text analysis MailScanner Virus scanner and spam detector SpamBayes Bayesian anti-spam classifier written in Python

Return to our complete collection of recommended free and open source software including our latest additions.

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