SpamAssassin is an open-source spam filtering platform that uses a combination of rule-based, DNS, and fuzzy checksum techniques to identify spam emails. It is designed to be run on a server and can be integrated with various email servers, including Postfix, Sendmail, and Exim.
With over 20 years of history, developed by the Apache Foundation, SpamAssassin has built a well-deserved reputation as one of the most excellent free spam protection tools. As a result, it is widely used by email service providers and individuals to help reduce the amount of spam in their inboxes.
Today’s release of the brand new major 4.0 version is a significant step forward in developing this software. So let’s see what’s new.
SpamAssassin 4.0 Highlights
Over the previous 3.4.6 releases, dated back in April 2021, SpamAssassin 4.0 features numerous tweaks and bug fixes. Above all, it includes major enhancements that significantly improve text handling in international languages.
Namely, support for the UTF-8 encoding text has been completed and greatly enhanced to allow native UTF-8 processing. As a result of this enhancement, SpamAssassin 4.0 is expected to perform significantly better at detecting and blocking spam-containing content written in languages other than English.
On top of that, the Bayes plugin has been improved to avoid popular terms, often known as noise words, also written in languages other than English. And while we’re on the subject of plugins, we can’t help but mention that SpamAssassin 4.0 includes three new ones. Here’s who they are.
- ExtractText: Extracts text from message sections using external tools and then sets the text as the rendered part.
- DMARC: After parsing DKIM and SPF data, the plugin checks if emails match the DMARC policy.
- DecodeShortURLs: The plugin looks for URLs shortened by a list of URL-shortening services. Then, it adds this URL to SpamAssassin’s list of extracted URIs, which may be accessible by URI rules and plugins like URIDNSBL.
Aside from the features stated above, SpamAssassin 4.0 includes a few others that we should mention. First, all rules, functions, command line arguments, and modules containing the terms “whitelist” or “blacklist” have been renamed “welcomelist” and “blocklist,” respectively.
Moreover, meta-rules no longer use priority values; instead, they are evaluated dynamically when the rules on which they rely are completed. Finally, we’ll mention that SpamAssassin 4.0 is the result of 18 months of hard effort by the developers, and it includes a long list of bug fixes, which you can view here.
For more about all novelties, you can refer to the release notes.