How to lock a single email?

baltwo wrote:
Easiest thing to do is create an account for her, change the password for your account, and turn off autologin.

baltwo wrote:
Why bother? OS X's security is build on separate user accounts, wherein each retains privacy.

Dave Sawyer wrote:
There is no way included in Mac OS X to prevent anyone who has access to your user account from seeing any given message in Mail. If you don't want your girlfriend reading specific email messages, it's probably most practical to just save them somewhere outside of Mail and delete them from Mail. Or as has been suggested give her a separate Mac OS X user account and then log out of yours when you're not using your computer.

And no, there's no way to prevent Spotlight from being able to find any given file in a user account unless you place that file in a secure disk image or use another security utility such as Espionage which says it can also lock mail, though I don't know if can lock a single message (I think it only locks folders which would mean it possible could lock a mailbox, but not just a single message).

Regards.