I received over 500 spam reports form a user that doesn't exist on my site. usually I can look at the username of the person who reported the message as SPAM because Amazon SES ends the entire message to me. In the "Hi Username" area it always says the correct username. 

However, I received a bunch of reports today where the username is not a member of my site. See below the username in the screenshot. I have no user by that name. 

Anyone know what's going on or experience this as well?

 

That is typically a language string that was not swapped out properly when the email was rendered on a site that supports multiple languages.

I could only recommend submitting a ticket so we can investigate.

Done.