I have a Gmail account of the form email@example.com. I just got email from Google saying there was a new sign-in half an hour ago on Internet Explorer (which I haven't used in the last few days) to firstname.lastname@example.org. I have two factor authentication set up, and didn't get any corresponding text message.
Is it the case that this is actually a different account, Google recognizes the account name with the extra digits as different for sign-in purposes, and it's just a bug in the notification system that it truncated the digits when deciding whether I needed to be notified? Or is there something going on that I need to worry about?