Inspecting it more closely, I was pretty confident this was a legit Google alert. The email address of the sender is , and Gmail itself tells me it's mailed by gaia.bounces.google.com and signed by accounts.google.com.

Is no reply accounts Google com a legit account?

The sender's address, no-reply @ accounts.google.com, spoofs what appears to be an official Google address. There is not an easy way to detect this. Instead of clicking a link in a message, go to Google or your gmail account via a known, good website address.

How do I know if my Google security alert is real?

Check for suspicious account activity

Go to your Google Account. On the left navigation panel, click Security. On the Recent security events panel, click Review security events.