Is the mail that came from gaia bounces google com legit?
I've received a suspicious mail in my Gmail inbox, about my password being exposed It comes from gaia.bounces.google.com and is signed by accounts.google.com. But there are two weird things about it:
It is written in Portuguese. I live in Spain (but near the border with Portugal, just in case that's relevant) and usually receive Google mail in spanish.
The mentioned account is a @hotmail one I use as a backup account, not the main Gmail one. It's been listed on haveibeenpwned.com a while ago but I changed all my passwords a few months ago when I started using a password manager.
I cannot see any problem with the signature, and the links on the mail seem legit. I've checked the certificate on the linked website and read this. Is this legit? Does Google warn about other non-Google accounts?
The email you've received from gaia bounces google com is legit, it is signed with the correct certificate of google. However, you are not the first one to raise a red flag for this one, the whole security industry specialised in social engineering is applauding google for the great "phishing attempt". To answer your question, yes google is checking databases of leaked credentials also for your recovery email address. Chrome now has functionality for checking hashes of your passwords (to any account on any website you're logging into) with their database of leaked credentials. This is part of their safe browsing feature.