Dummy Messages

What are dummy messages?
Dummies are messages sent out by mixmaster as cover traffic, to make traffic analysis of real message even more difficult. Remailers are constantly sending out dummies that go from hop to hop and finally, just disappear. They carry no actual message.

Mix can provide cover traffic for you as well. They will be sent out at the time you send your actual mixmaster messages. If you use this feature, be aware that you will see more messages sent in the SMTP dialog. For some reason, users are sometimes confused by this. They send a mix message with 3 copies and mixmaster creates and sends, say, 5 messages. That's how it works.

If you would like to use dummies, yourself, it's easy to tell mixmaster what you want.

Open mix.cfg on the View menu. You'll find the entry:

OUTDUMMYP 0

This entry tell mixmaster to not send dummies at all. By increasing the value to something greater than 0, you can have mix send dummies with your regular mail. You'll probably want to experiment with various values. From the mixmaster man page:

OUTDUMMYP
 
Probability that Mixmaster will generate dummy messages at SENDPOOL 
time. If the pool is processed frequently, this should be a lower value 
than if there are long intervals between pool processing. Examples: 50 
means on average, one dummy message will be generated per pool 
processing. 80 means four will be generated. 0 means no dummy messages. 
Remailer default: 90. Client default: 3.
Online: http://mixmaster.sourceforge.net/manpage.html