This is the "nymserver" code that I run on alpha.c2.org.  The documentation
may be a bit sparse, but I think it's usable.

You need to set up a mail domain with a MX pointer to your system. 
Configure sendmail to forward all messages for that domain to the 'main'
script, with the username as the first argument.  If you need to make a
setuid wrapper to call it, put the userid in wrapper.c and compile that.

Set all the #defines in the C programs, and the variables in the shell
scripts.  These are mostly self-explanatory (I hope) and set your
directories, hostname, etc.

Generate a public key.  PGP is called from the 'anonserv' script.  Put
your pgppass in there.

Set up the help file and put the PGP key in it.

Compile everything:
 gcc sendbatch.c -o sendbatch
 gcc processmsg.c -o processmsg
 gcc getfrom.c -o getfrom
 gcc getnym.c -o getnym
 gcc pgpext.c -o pgpext

When addresses are created, it creates in the nyms directory two files:
a (name).password file and a (name).replyblock file.  You can create
files ending in .forward which forward messages to the address in them,
but do not encrypt anything.  You should do this for root, postmaster,
admin, etc, as well as a nobody.forward that goes to /dev/null.

When mail comes in, it goes in the in.queue directory.  Running sendbatch
processes these messages and sends them out.  This should be run at regular
intervals by cron.

