What's a Nym?
Nym is short for pseudonym. Often book authors write under pen names, or pseudonyms. In terms of privacy/anonymity a nym is a pseudonym by which you have 2-way untraceable communication with others.
What's a Nymserver?
A nymserver is essentially an email service that provides untraceable mailboxes for anyone--at no charge. In other words, this service allows you to sign up using a pseudonym for the purpose of correspondence. Like I said, this service is free and your incoming/outgoing mail cannot be traced to you.
How do I send my message, so it can't be traced?
You simply send the outgoing message to the nymserver, via a mixmaster chain.
You PGP sign the message, so the nymserver will know it's yours.
How can I receive replies, if they can't be traced to me?
The process of making your incoming mail untraceable is rather straight-forward and easy to understand. You may be
acquainted with the USENET news. If not, it's a major collection of forums,
also called newsgroups, where people discuss everything under the sun. There are many thousands of newsgroups, with each devoted to specific discussions. One of those newsgroups is called
alt.anonymous.messages. The purpose of this group is not discussion but
to provide a community mailbox for people to leave and/or pickup mail while remaining anonymous.
Your incoming messages are retrieved from there. It's like communicating via
personal ads in the newspaper.
Can't an attacker see me download my messages?
Yes and no. Yes they can see you get messages, and no, they don't see which are
yours. There is a bit of a trick to this. You always download every message
available and then just keep those belonging to you. All the rest are discarded. That way, anyone watching you cannot know which messages are yours. You get your mail, yet the mail cannot be traced to you. This is how the nymserver delivers mail to you. It's really pretty slick!
Sounds like it may be complicated. Is it?
Not really. You can use QSL to signup for the nym service and also to forward your outgoing mail to the nymserver for delivery to the recipient.
All communication is done via mixmaster chains. Thus, you have no
direct contact with the nymserver so no one can know you have a mailbox there.
A companion program for QSL, QSAam is designed to retrieve and decrypt your mail and pass it on to QSL so you might reply . It handles the entire job of downloading all the messages and keeping those that belong to you.
Other Considerations
It's important to know that all messages, including outgoing mail, are encrypted to the nymserver so no one along the line can read what you have written to the recipient--not
even the final remailer. The nymserver decrypts the message and forwards it in plain text
to the recipient just like mixmaster messages. Of course, you have the option of PGP signing/encrypting the message to the recipient, if you don't want the message delivered in
plain text. This delivery is direct to the recipient, not to
alt.anonymous.messages. That's used only for you to pickup your mail.