i got a email today that i linked below.. i do not own a r520 nor do i use IDrac. does this mean someone was able too get into my unraid account? is there anything i need to check? so far i have logged out of unraid.net on my server. changed my password, and changed my auth provider. is this good enough? any way i can tell if they are still connected? any help is much appreciated 

Possibly, someone just set the wrong address for his notifications.

Answered over on Discord, notification is from Dell's idrac (out of band management), unrelated to Unraid.
OP mentioned they had sold their Dell server long ago and wasn't reset to default, most likely left email creds in notifications and new owner started setting up alerts.