Private Dialog is a Business::PIMS & Calendars software developed by Firmas Digitales SRL. After our trial and test, the software was found to be official, secure and free. Here is the official description for Private Dialog: Private Dialog implements extremely strong cryptography. You can "invite" any person to accept your encrypted mails and in such a way you can protect sensible information in an unbreakable way.
The product adjusts itself to any popular mailer (Outlook, Outlook Express, Eudora, etc) you can download Private Dialog 270 free now.