Rspamd is an anti-spam system designed to work faster than SpamAssassin by using the event model and various optimizations. Its most important features include regexp and Lua rules for filtering different parts of messages, a number of built-in functions for analyzing messages, fuzzy hash support, SURBL filters, email and character table support, a control interface for remote managing and stats gathering, a Lua plugin system, statistics support (OSB/Bayes), and an AJAX-based Web interface.
MailSteward will archive all of your email in a database for easy retrieval, without touching or modifying the email in your email client program. Just click on the Store Email in Database button and MailSteward will go to work storing copies of all your email, both text and HTML versions, and attachments, into a relational database file. You can then retrieve email and attachments from the database by searching on Date, From, To, Subject, Mailbox, or Body text.
redWall is a bootable CD-ROM firewall which focuses on Web-based reporting of the firewall's status. It includes Snort, snortsam, dansguardian, and support for fwbuilder, squidguard, reporting (using BASE/sarg/ntop/webfwlog), VPN (Openswan/PoPToP/Openvpn), Spam Filtering (spamassassin, dcc, razor2, clamav, amavis-new, dspam and maia mailguard), and mail-based, alerting. Configuration data are stored on a floppy or USB disk.
OfflineIMAP is a tool to simplify email reading. It allows you to read the same mailbox from multiple computers and ensures that your changes will be automatically reflected on all computers. You can use various mail clients to read a single box or read mail while offline with full synchronization when you reconnect. You can read IMAP mail with readers that lack IMAP support (same goes for SSL). OfflineIMAP's multithreaded synchronization algorithm performs between 10 and 60 times faster than many mail readers' internal IMAP support, and it can be used even with mail readers that support IMAP already. There are five available user interface modules, including scripted execution, an interactive terminal interface, and GUI interfaces.
Policyd v2 (codenamed "cluebringer") is a multi-platform policy server for popular MTAs. This policy daemon is designed mostly for large scale mail hosting environments. The main goal is to implement as many spam combating and email compliance features as possible while at the same time maintaining portability, stability, and performance. Its features include detailed policy and group specification, access control, helo/ehlo checks (helo randomization prevention and RFC compliance), SPF checks, Greylisting, Quotas, and Amavisd-new integration.
Heirloom mailx (formerly known as "nail") is derived from Berkeley Mail and provides the functionality of the System V and POSIX mailx commands. Additional features include support for MIME, IMAP (including caching and disconnected use), POP3, SMTP, S/MIME, international character sets, maildir folders, message threading, powerful search methods, scoring, and a Bayesian junk mail filter. Mailx can be used as a mail batch language in nearly the same way as it is used interactively. It can thus act as a mailbox filter, can fetch mail from remote accounts, and can send files as attachments.
Vipul's Razor is a distributed, collaborative, spam detection and filtering network that exploits the broadcast characteristic of spam distribution to limit its propagation. The primary focus of the system is to identify and disable an email spam before its injection and processing is complete. Razor establishes a distributed and constantly updating catalogue of spam in propagation. This catalogue is used by clients to filter out known spam.
GNU Mailutils is a rich and powerful protocol-independent mail framework. It contains a series of useful mail libraries, clients, and servers. These are the primary mail utilities for the GNU system. The central library is capable of handling electronic mail in various mailbox formats and protocols, both local and remote. Specifically, this project contains a POP3 server, an IMAP4 server, and a Sieve mail filter. It also provides a POSIX "mailx" client and a collection of other handy tools.