Even cypherpunk remailers have their limits. There are still security holes that can be used to discover the real sender of a message, even when it has been "chained" through multiple remailers.

Mixmaster is the next generation of remailers, using advanced techniques to make most methods of tracing remailed messages useless. It requires the use of a special client to generate the Mixmaster messages.

Mixmaster remailers, also known as "Type II" remailers, were designed to be even more secure than cypherpunk remailers. Most of the attacks that work against "Type I" remailers are useless against Mixmaster remailers. It requires a special client to compose messages.

A comprehensive list of all known Mismaster Remailers is available from EFGA - This list tests all known remailers for their response time and reliability. Use this data to pick remailers for your anonymous messages.

Mixmaster & Remailer Attacks A discussion on vulnerabilities in cypherpunk remailers, and a description on how a more secure system can be implemented.

Mixmaster Remailer FAQ Frequently Asked Questions on Mixmaster, with answers.

Tools

Download the Mixmaster client
Users can obtain the source (most useful for UNIX plaforms) or the DOS version, which can be used together with Private Idaho.

Jack B. Nymble v2.1+
A full-featured Windows 95/NT remailer client for use with anonymous and nym remailers. It provides full SMTP and POP3 support, including MIME mail, attachments, and automated PGP encryption and decryption.

Potato v2.3+
A DOS based software package which operates well in all versions of Windows. This remailer utility provides for the preparation of anonymous and nym messages, including MIME mail, attachments, RichMail, and automatic PGP signing and encryption. Potato also includes the Nym Editor, which allows for sophisticated nym account configurations, including multiple reply blocks.

Decrypt v2.1+
This DOS program integrates well with all versions of Windows, and includes a Windows95 installation program. Decrypt provides for automatic decryption of nym mail. Given the PGP passphrases, it will completely decrypt mail from multiple accounts. Decrypt can also import/export messages to some email apps, such as Netscape, Eudora, and Agent, where messages can be viewed and attachments saved.

Private Idaho v 3.4+
An anonymous remailer utility for Windows, supporting PGP, the cypherpunks remailers, Mixmaster, and nymservers. It too automatically configures itself based on this remailer list. The Private Idaho Online Documentation is a good source of help for using the program.

Mailcrypt v3.5.7
Directly supports remailers and PGP encryption (up to v5.0). It implements many of the same features as premail, but in Emacs. Anyone who uses Emacs for their news and mail should definitely check this one out. It can automatically load the information from this remailer list.

Reliable v 1.0+
Operate your own remailer. Remailer server software for Win95/98/NT which turns a standard PC and mail account into a full Cypherpunk and Mixmaster remailer. May be used to run a public remailer on a dialup or dedicated connection, or to run a local system remailer for your own security benefits. Includes a full online Remailer User's Manual with glossary of remailer terms, as well as a complete Operator's Manual.

MixFit
A MacOs application for mixmaster formatted anonymous remailer messages.

Further Reading and Resources

Client Setting via anon.efga.org

Mixmaster Remailer FAQ

Mixmaster & Remailer Attacks