It is important to keep your email encrypted to prevent your personal information do not fall into the wrong hand especially when accessing your email through a public wireless or non-encrypted network.
Gmail’s automatic HTTPS setting allow us to encrypt our email as it travels between web browser and server. According to Wikipedia, HTTPS (Hypertext Transfer protocol Secure) is a combination of the Hypertext Transfer protoco with the SSL/TLS protocol to provide encryption and secure (website security testing) identification of the server. Bank and Credit Card website use this protocol to protect our financial data.
To make your Gmail always use HTTPS setting:-
1st you need to click on setting link which located at the top right hand corner.
2nd, select “Always use HTTPS“. Your Gmail will automatically redirect to the secure version.