Penet remailer

The Penet remailer (anon.penet.fi) was a pseudonymous remailer operated by Johan "Julf" Helsingius of Finland from 1993 to 1996. Its initial creation stemmed from an argument in a Finnish newsgroup over whether people should be required to tie their real name to their online communications. Julf believed that people should not—indeed, could not—be required to do so. In his own words:

Implementation

Julf's remailer worked by receiving an e-mail from a person, stripping away all the technical information that could be used to identify the original source of the e-mail, and then remailing the message to its final destination. The result provided Internet users with the ability to send e-mail messages and post to Usenet newsgroups without revealing their identities.

In addition, the Penet remailer used a type of “post office box” system in which users could claim their own anonymous e-mail addresses of the form anxxxxx@anon.penet.fi, allowing them to assign pseudonymous identities to their anonymous messages, and to receive messages sent to their (anonymous) e-mail addresses.