Yahoo Mail, like all other mail providers, can only protect your email while it is in their possession. But just like a postcard, your email has to leave the post-office (Yahoo!) to get delivered, and like a postcard, everywhere it goes, people can read it… Not just the intended recipient. That's why it's important to hide your email from prying eyes with MailCloak.
Fewer Clicks, More Security.MailCloak was designed first and foremost, to be easy to use. Our browser plug-ins are fast, even on slow machines, and require minimal user input to provide —quality encryption.

If you are a yahoo user, chances are you email people who use gmail, hotmail, and tons of other email services. With MailCloak, you can be sure that whatever your contacts use, there's a MailCloak plug-in suitable for them, so don't worry, just cloak.