Oh no! I was in a hurry and made a mistake?

I wrote my teacher an e-mail, and made a really bad typo on his name. He has a really confusing, Yugoslavian name, so I have a good excuse. Plus, I was in a hurry. But it's not my current teacher. He was my 9th grade teacher. I was just saying "hi", and misspelled his name in the headline. Do you think he will get mad and not right me back? Do you think he won't even open it now?