Gmail has always been widely under attack, however, most of the times user’s account are compromised because of phishing, rather than because of the lack of security @Gmail.
HTTPS or HTTP_Secure, is a secure way of transmitting data to and fro on the web. Unlike HTTP, HTTPS data is encrypted before a transfer occurs. This makes data transfered through HTTPS hard to snoop on, and allows users a safer way to browse the web.
Gmail did have an option for users to use HTTPS as default, through a Gmail Labs feature. Today, Google graduated the feature out of labs. This means that all Gmail users will now automatically start using HTTPS by default. Users have an option to disable HTTPS by default by visiting “Settings -> Labs” and choosing “Don’t always use https”
However, HTTPS alone cannot save you from being hacked. There are several other ways in which you can protect your online accounts. The first rule is, NEVER click on links in emails sent by strangers. The second rule is, NEVER download content that are sent by strangers.
You can also make use of a Gmail Labs feature called Anti-Phishing Key, which allows you to distinguish between legitimate and spam email. However, this feature has a limited scope and only supports eBay and PayPal right now.
If your Gmail account is hacked, you might want to read what steps you should perform in order to check the safety of your Gmail Account