Email encryption

[manishrathi]

How can I encrypt an email ?
Is there an option available to encrypt an email ? I came across this question, while I was studying about windows vista operating system.

Question was "You need to encrypt all email messages that are sent to co-worker. You also need to prevent Microsoft Windows Mail from requesting appropriate certificate for each email message sent to co-worker"

Solution given was "Import the certificate of co-worker into the co-worker's contact properties"

How to import certificate in the co-worker's contact properties ? I checked a contact property in Yahoomail, I could not find any field from which I can import certificate. How to import certificate in yahoomail or Gmail or Hotmail ?
Or is this functionality not provided in any of these ? In what kind of email service, is this functionality provided ?

Thanks

[thehacker010]

I believe that is talking about importing a digital certificate in Windows Mail. Gmail uses basic text encryption and HTTPs, but if you need digital signatures you will have to use some client like Outlook that supports that feature. I believe there is also some sort of S/MIMI Firefox addon which adds support to Gmail's website, but I have never used it.

I believe this addon will allow you to add digital signatures and encrypt emails using the recipient's public key.
https://addons.mozilla.org/en-US/firefox/addon/592