Release Notes: A new database backend called "list". New options to set the value of X-Spam header, keep a plaintext mapping of hashes to tokens, and maintain a deny list. Allow and deny lists can now list domains as well as individual email addresses.
Release Notes: Tokens now "age", which keeps the database smaller and more accurate. Speed improvements have been made in the default binary tree backend. Per-user databases are now given more weight than the global database. Some new token types have also been created.
Release Notes: The tokeniser was improved further to recognize distinct URLs and to compress whitespace. Additional filters for IP-based URLs and virus attachments were added.
Release Notes: Spam scoring now uses the more accurate Robinson method. Extra tests have been added to enhance spam detection. Token pairing has been added to enhance accuracy.
Release Notes: Logarithmic scaling of the spam probabilities has been implemented. Benchmarking and informational options have been added. A database-independent backend storage module has been written to remove the dependency on GDBM or Berkeley DB.
Release Notes: Options for adding a numerical rating header and pruning the database were added. The tokenizer now strips HTML in a sensible manner and preserves hostnames. Debian build support was added, and new wrappers for Berkeley DB remove the dependency on GDBM. Tokens are now hashed for privacy, so words from emails no longer appear in the database. All users will need to rebuild their databases using the "--train" facility after upgrading.
Release Notes: Support for using both system-wide and per-user spam databases in tandem has been added, plus improved MIME handling, better training, and some minor bugfixes.