Currently there are two executables hato-mta and hato-classify.
Hato is still in early beta, so you probably won’t want to run it as
your primary mail server yet. If you run as a non-root user it will by
default start up on port 5025, otherwise as root it starts on the
standard port 25. You can also specify the port with the --port
option. The default mail spool directory is /var/mail/ for root, and
$HOME/hato/var/mail/ for non-root users.
You can interactively in a REPL fashion by specifying the --test
option. This handles a single non-threaded SMTP session from standard
input, and provides the additional EVAL SMTP command to evaluate
arbitrary Scheme expressions:
EVAL (set! log-level (+ 1 log-level))
A single file-name argument may be provided in test-mode which will then
be used instead of standard input for batch tests. The --debug
option will make hato-mta output more verbose debugging information.
hato-classify is a stand-alone adaptive spam classifier which can use a number of different probabilistic methods, including Markov chains (the default) and naive Bayesian probability. It uses the same libraries and can use the same database file as the spam filtering provided by hato-mta.
The two basic modes of operations are:
hato-classify -exit-code
Filters standard input and exits with a return value of 0 if not spam and 1 if spam, compatible with many other filter.
hato-classify -insert-header
Filters standard input and prints it back to standard output with two MIME headers inserted as follows:
X-Spam-Classification: [HAM or SPAM]
X-Spam-Probability: 0.5
See hato-classify -help for more information.