DSPAM is a server-side statistical anti-spam agent for Unix email servers. It masquerades as the email server's local delivery agent and effectively filters spam using a combination of de-obfuscation techniques, specialized algorithms, and statistical analysis. The result is an administratively maintenance-free, self-learning anti-spam tool. DSPAM has yielded real-world success rates beyond 99.9% accuracy with less than a 0.01% chance of false positives.
John the Ripper is a fast password cracker, currently available for many flavors of Unix, Windows, DOS, BeOS, and OpenVMS. Its primary purpose is to detect weak Unix passwords. It supports several crypt(3) password hash types commonly found on Unix systems, as well as Windows LM hashes. On top of this, lots of other hashes and ciphers are added in the community-enhanced version (-jumbo), and some are added in John the Ripper Pro.
ClearOS is an integrated network server gateway solution for small and distributed organizations. The software provides all the necessary server tools to run an organization including email, anti-virus, anti-spam, file sharing, groupware, VPN, firewall, intrusion detection/prevention, content filtering, bandwidth management, multi-WAN, and more. You can think of it as a next generation small business server. Through the intuitive Web-based management console, an administrator can configure the server software along with integrated cloud-based services.
MIMEDefang is a flexible MIME email scanner designed to do all kinds of email processing, including anti-virus scanning, anti-spam scanning, replacing parts of messages with URLs, adding boilerplate disclaimers, and so on. It can alter or delete various parts of a MIME message according to a Perl-based policy filter. It can also bounce messages with unacceptable attachments and modify SMTP response codes on the fly. It works with the Sendmail 8.11 and newer "Milter" API, which makes it more flexible and efficient than procmail-based approaches.
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.
fdm (fetch and deliver mail) is a simple, lightweight replacement for mail fetching, filtering, and delivery programs such as fetchmail and procmail. It can fetch using POP3, POP3S, IMAP, IMAPS, or stdin, and deliver to a pipe, file, maildir, mbox, or SMTP server, based on a set of regexps. It can be used for both single user and multiuser setups, and is designed with privilege separation when running as root.
PHP MIME Mail decoder class is a PHP class to parse and decode MIME email messages. It supports decoding single RFC 2822 MIME messages or archives that aggregate multiple messages in the mbox format. It can decode messages read from files or data strings. The bodies of multipart messages can be decoded into distinct sub-messages. Optionally, the message body data can be saved to separate files, so the class can handle messages larger than the available memory. The parser can tolerate some syntax errors in malformed messages that are not compliant with RFC 2822.