This question already has an answer here:
I got two emails this week from Gmail, claiming to have prevented "suspicious sign-in attempts" to my account. These emails came from the address: firstname.lastname@example.org (using the name "Activity Alerts"), and were located in my inbox (not spam, where faked emails should go).
Image of one of the emails:
[My name redacted],
In the past 48 hours we have detected 6 failed sign-in attempts to your Google Account, [My email redacted]. We have prevented further sign-in attempts from the responsible address in case this was a hijacker trying to access your account. Please review the details of these attempts:
IP Address: [Redacted]
If you do not recognize this address, someone else might be trying to access your account. These sign-in attempts were unsuccessful, so no action is required. However, you may wish to reset your password for greater security. Find out how at http://support.google.com/accounts?p=reset_pw
If this was you, you may safely ignore this email. The address will be allowed to sign in again within 24 hours.
The Google Accounts Team
Are these legitimate? I've never seen the email address before, but the only link on it (to learn how to reset my password) goes where it says and doesn't ask for any login information. If it is legitimate, is my account safe or compromised?