Bike Bubba asks if there is support for encryption in Lotus Notes (now available for Macintosh, btw).
The answer: yes!
One would need Lotus Notes (but that is understood), GnuPG or PGP (both free -- only the former is open source, though.), gpg4win and a commercial package: PGPNotes.
Note for MS Outlook users: you may also use gpg4win and GnuPG for your encryption needs.