Password prompts in yahoo.

Hello,

I will just like to find out whether it is possible to still block viewers from reading your email when you decide to follow the useful feature offered by yahoo, where it asks permission to remember your password and email address, everytime you log on to yahoo mail. Should I just remove my email address and password altogether, so that every time I log on, it's safe and no one can see my mail. However, if there's a way where I can still use the useful feature but, a firewall embedded in it to block other users from easily reading my email, I will really like to know how. Could you please assist me?

Thanks in advance for your assistance.

Mel.