MailStore - MailStore Home - A 100% free single-private-user desktop solution
Encipher.it - Encrypting email with Encipher.it is a simple way to protect your sensitive data.
Mail Backup X - Your one stop mail backup and archiving tool for Mac.
Lockbin - Lockbin is a web application for sending private email messages and files.
Mail Archiver X - Mail Archiver X protects one of your Mac-based small business' most important assets.
secserv.me - Create client-side encrypted message. Chat anonymously client-side encrypted.