Have you ever wanted to send a BCC secret message as part of a larger group email? Well this feature is now available to Gmail and Firefox browser users with the BCCThis add-on. The tool will add a second collapsible text box to the bottom of Gmail's compose view that will allow you to add a second message as part of the larger email to any of it's recipients.
Bccthis for Gmail is a free download add-on for Firefox.