Security is major concern when you send your private data through internet. Secured Socket Layer (SSL) is an internet protocol for transmitting private data through internet securely. It uses two keys to encrypt data − a public key known to everyone and a private or secret key known only to the recipient of the message. It gives extra layer of security to your account.
In yahoo mail, you may have noticed that the account log-in page uses SSL but once you log in your account it is not. You can verify it by log-in your yahoo account. URLs that require an SSL connection start with https instead of http
How to enable or disable SSL
1. Go to Yahoo! Mail, click the gear icon in the upper-right corner of the window, and select Mail Options from the menu that appears.
2. Click General at the left.
3. At the bottom of the General menu at the right, check the box next to Turn on SSL, or uncheck it to disable SSL.
4. Click Save.
You should see a lock now in front and https in front of the web address.
Your Internet browser must support SSL in order for it to be used when you visit Yahoo! Mail. Please see the list of supported browsers by visit http://help.yahoo.com/kb/index?page=content&id=SLN3257