Different than the other thread about a spam email. I just got an email that definitely seems to be from unity3d.com if I’m reading my email headers right, but the subject is “Here goes subject line” and the text is the lorem ipsum text. Get those new interns some coffee before they accidentally click send again! 
Got the same email 
Yes, sorry about that. We are moving over to a different e-mail tool at the moment, and it is a bit wonky. Not spam, just the e-mail system firing off template e-mails for no reason 
I had the same email this morning as well although strangely enough it got sent to the junk folder of my old email address for Unity rather than the one I’m currently using.
It seems to be affecting only a certain number of accounts, which could explain why your old one received it but not your current one.
FWIW I received the email properly yesterday.