This site is available via https and it uses a CACert certificate, please install the CACert root certificate if you haven't done so already. See Aktivix:Certification for more information about certification.
Aktivix encourages the use of encrypted email communication for reasons of privacy and security and plainly as a matter of good practice. It is OK to send postcards from your holiday, but there are surely many letters (or emails) that you wouldn't want the postman (or snoopy) to read.
Email encryption is not so difficult once you know how :)
There is a collection of information on the Aktivix:EmailSecurity page with most of what you will need to get started using encrypted email and learn about things about safe and secure communication.