GNU Privacy Guard DNS Keyserver Client enables sending and retrieving OpenPGP keys with GnuPG to and from DNS-based keyservers. DNS-based keyservers offer several advantages over traditional HTTP-based ones, such as distributed caching, server fail-over, and geographical optimal server selection, etc.
Kerio MailServer is a secure corporate Internet messaging server for SME. It integrates SpamAssassin, McAfee anti-virus, SSL encrypted POP3, IMAP4, SMTP, WebMail (HTTP) and WAP protocols, attachment/content filtering and a MAPS/user-defined anti-spam database. It supports multiple domains, automated replies, SMS notifications, shared and public folders, email folder backup, full Active Directory implementation, mailing lists, and shared contacts. It runs on Red Hat 7 and 8, Windows 98/ME/NT/2000/XP, and Mac OS X 10.2, and is available with English, French, Dutch, and German user interfaces.
Enigmail is an extension for the mail client of Mozilla, Netscape 7.x, and Mozilla Thunderbird that allows users to access the authentication and encryption features provided by the popular GnuPG software. It can encrypt/sign mail when sending, decrypt/authenticate received mail, and import/export public keys. It supports both the inline PGP format and the PGP/MIME format, which can be used to encrypt attachments, and is cross-platform, although binaries are supplied only for a limited number of platforms. Enigmail uses inter-process communication to execute GPG to carry out encryption/authentication.
Akeni Messenger Jabber Edition is a cross-platform client for Jabber compliant servers. It features an XML-based messaging protocol, private chatting, conference mode, broadcast messages to groups of people, message log, a typing indicator, a full-featured rich-text editor, emoticons, and powerful online presence management.
yaspi (Yosi's Anti-Spam POP3 fIlter bot) is a POP3 mail-scanner specifically made to combat mail bombings caused by viruses (i.e. Swen). It connects to the POP3 server, inspects the messages, and deletes the infected ones without ever downloading them. Its most interesting feature is that it can automatically send abuse reports to the ISPs from which the infected mails originated.
Akeni Instant Messaging Server Pro is a client/server instant messaging platform that allows companies to host their own secured private IM system. The client has an user interface similar to AIM, ICQ, or MSN Messenger. It supports all the standard IM features such as chat, group conference, presence management, file transfer, offline messages, and emergency alert/notification. Extra features include contact management and optional tabbed chat sessions. The server has advanced administration tools for managing user accounts, client-side logging capabilities, and peer-to-peer file transfers. It can be set up on a private network without connecting to the Internet, and can easily be set up for use inside and outside of the company firewall.
SPF is a new strategy for preventing junk mail. The present SMTP standard for email allows anyone to forge anyone else's email address. SPF verifies that the Sender address of an email message matches (according to some policy) the client IP address that submitted it. libspf2 is a complete and robust implementation of SPF which provides support for many MTAs. Support for new MTAs is in progress.
HashCash is an anti-spam, anti-DoS system for email. The concept centers around the sender of the mail completing a computationally expensive task (in this case, generating hash collisions) that the recipient can verify very quickly. This allows the sender to "pay" for transport in CPU cycles, creating artificial scarcity. Programs are included to add payment to messages (for the sender) and to verify message payment (for the recipient).