Some miscellaneous free source
is available
as well as some
anti-spam tools
including the primary source of the DCC spam filter.
You can download the Rhyolite
Software self-signed certificate into some browsers.
It is also available in PEM format
for use with SMTP clients and servers that understand SMTP-TLS.
It is generally a waste of effort to send mail to any rhyolite.com address from unwelcome IP addresses, unwelcome domain names, or listed free providers. Mail messages from those IP addresses or domain names may appear to be accepted by the Rhyolite Software mail system, but are generally reported to the DCC with target counts of MANY and then archived, unseen by anyone.
Contact Vernon Schryver at vjs@rhyolite.com or use the web form. Do not send to the spam trap.