CryptWit

The fact that emails can be intercepted should make you think twice before mailing an important document or privileged information. Fortunately, CryptWit provides a reliable solution for Outlook users. It gives you the possibility of sending compressed and highly encrypted email messages. Even if they are intercepted, your emails will be inaccessible without the correct password.

CryptWit is compatible with MS Outlook 2007 and all later versions and it works on Windows XP and later editions, up to Windows 8. The add-on is free and it can be installed in a few moments. It requires .NET Framework 3.5, which can be downloaded and installed without any effort.

CryptWit doesn't come with an interface of its own and you can't launch it separately, like a traditional application. Once installed, it will integrate with MS Outlook automatically. The only difference you will notice on the mail client's interface is a new Send button, on the new message window. You can type your message and attach files as usual, but instead of clicking Outlook's Send option, you must click CryptWit's button.

When you send an email, CryptWit will ask you for a password. The same password will be used by default for all future messages, but you can change it at any time. The add-on will encrypt attached files as well. The message itself will be sent as an attached HTML file. Furthermore, all attachments, including your message, will be compressed in highly encrypted Zip archives. To extract their contents, the recipient will need your password, which you should send through other means.