Back in 2008, Gmail had introduced a new feature which allowed you to track suspicious access to your account. This feature was gradually made more prominent in 2010 through Google Suspicious Login Protection. Google has in fact taken this protection further with the introduction of two-step login verification thanks to Gmail accounts in China being hacked and several other security measures they have put in place.
However, your Gmail account can get hacked nevertheless (Read: How to find if your Gmail account is hacked and what to do) and there is nothing you can do about it. But what if your friends email account gets hacked and you receive a desperate email from them asking for cash or some help?
Well, this is not unusual and there are several times when you might receive emails from your contacts which come from a legitimate email address asking you for financial help. These messages "might" be genuine but many a times these are nothing but online scams. Thankfully, you can avoid such scams if your friend is using a Gmail or Google Apps related email address. How? Well, thanks to several security measures, Gmail now display a suspicious email warning if they believe that the account has been hijacked.
Take for example an email from my friend who is on my contact list. The above screenshot displays a warning saying that the message might be suspicious (and it is indeed because my friends account was compromised). This is definitely a good feature because it will allow users to instantly know that something is wrong. Based on this message (and the content of the email), I alerted my friend and he confirmed that his account was compromised.
I am not sure if Gmail does this for emails from non-Gmail accounts, but it is definitely helpful when a email service is intelligent enough to know when an account has been hijacked. This information might be collected using several security measures, one of them might be the suspicious account login feature Gmail has. However, it might not just be limited to it.