Some of them are truly the most absurd thing I've ever seen. I think some of them actually think Notre Dame is trying to recruit their player instead of it being a mis-mailed piece of mass recruiting for summer high school camps.
As far as violations go, this would likely be a secondary violation, but maybe not. As I understand it, sending mail to someone is not automatically a violation... for example, Bill Snyder writing a hand written letter to Jace Amaro wishing him a speedy recovery, and many other examples of current coaches contacting current players for other schools.
When you read the mailer he was sent, it's just an invite to Notre Dame summer camps. I don't know if that even counts as a recruiting mailer.