Spam Emails (MAX+PLUS)

I have received almost 50 emails from university@altera.com over the last three weeks. I have tried three different phone numbers, replying to one of the emails and composing my own email asking for information from anyone at Altera and have not been able to contact a single human being via any of those methods. Each of the emails has a subject of "Your MAX+PLUS II Version 10.2, 10.1 & 9.23 Student Edition License" and only contain "Hard disk serial number: XXXXXXXX" with varying serials. I would like to know who they were originally intended for and how to stop them without blocking your email address.