OK I guess this is just me getting all OCD, but it still bugs me there. They've all been showing up in my spam folder since I marked the first one as spam, but it bugs me that I'm still getting them. I do check that folder when I see something there, just in case something important gets mistaken for spam by Google. (this is a gmail account btw)
It says it's from accounts@blizzard.com or something like that, but when I tell it to show me more info it says it's from Hotmail. I'm not sure if there's a way to block that address without missing out on REAL Blizzard mails, because it's masked.